Worldwide, 117.3 million people were displaced at the end of 2023, comprising 68.3 million internally displaced people, 43.5 million refugees and 6.9 million asylum seekers. A thinktank has further projected that these figures could reach up to 1.2 billion people in 2050, a number compounded by climate change. Specifically, a refugee is defined as a person who has escaped their country and cannot return because it is too dangerous. An asylum seeker is an individual who has left their country and formally applied for international protection in another country, but whose claim has not yet been processed or decided. Displacement is caused by many factors including conflicts, systemic violence, human rights violations, individual and group identities, and forced conscription among others, and while official routes are available for some when seeking sanctuary (e.g. resettlement schemes in the UK), many displaced people flee their countries through unofficial routes.

Trauma is a common experience of those who are displaced and can arise from: (a) the displacement process and (b) the resettlement process itself. Three distinct periods of displacement associated with trauma have been further defined as: (a) pre-migration, a time before deciding to leave a home country; (b) peri-migration, the period spent getting to a place of safety; and (c) post-migration, the time of resettlement into a new country. Each stage comes with its own challenges and potentially traumatic experiences. During these different periods, research has found that individuals experience traumatic events that include war, violence, a lack of basic needs, family separation and poor living conditions.

Such trauma is reflected in high rates of mental health problems, specifically high levels of post-traumatic stress disorder (PTSD) (31.5–43%). In the general population, trauma can have a significant impact on people’s quality of life, their functional and emotional behaviours, their physical health and mental health.

In displaced individuals, trauma presents with similar outcomes, such as increased rates of PTSD, depression, anxiety as well as through a reduced capacity to integrate into host communities. Some studies also report cognitive impairments affecting memory and executive function, as well as an increased risk of developing other psychiatric conditions like psychosis.

Social functioning

Social functioning can be further impacted by trauma and PTSD in the general population. Social functioning is defined as how individuals interact in society and their own personal environment.

More specifically, social functioning has been described as an individual’s engagement with their environment and capacity to fulfil roles in work, social activities and relationships with partners and family. This capability is crucial to the successful integration of displaced groups into a host country. Consequently, those who integrate better will thrive, contributing to a healthy society.Recommendations on how to enhance integration for displaced people include improving housing options, employment, language assistance and education, social inclusion, avoiding detention and a proactive approach to managing physical and mental health issues.

Trauma, however, has a profound impact on an individual’s ability to function in a new society. Given the high prevalence of trauma in this population, it is essential to understand integration and social functioning within the context of displacement, and while there is research on the impacts of trauma or PTSD on social functioning, the results are mixed. Some studies highlight the profound negative impact of trauma on various aspects of functioning in displaced groups, while others suggest the potential for improvement post-trauma. Although individual studies have examined different elements of social functioning, no review to date has synthesised how trauma or PTSD influences different areas of social functioning post-migration.

Study aims

Given the inconsistent findings in the existing research, a systematic approach is needed to clarify the relationship between trauma, PTSD and social functioning in refugees and asylum seekers post-migration. Our aim was to systematically review the literature to determine how trauma and PTSD affect social functioning in adult displaced groups. Specifically, we identified the aspects of social functioning most affected by trauma and analysed how various types of traumatic events influence these key areas.

Method

We adhered to the PRISMA guidelines in this systematic review, and submitted a protocol for the systematic review on to PROSPERO (CRD42024612834).

Search

The search strategy was developed using preliminary searches of the current literature and key terms identified were applied to the PICO (Participant, Intervention, Comparator, Outcome) framework (see Appendix A in the Supplementary material). Searches were then conducted between November 2024 and February 2025 in the following databases: EMBASE, MEDLINE, PsycINFO, Scopus and Web of Science. Grey literature was searched for on government websites, United Nations, the World Health Organization, Amnesty International, Freedom from Torture, Hestia and Helen Bamber. Within the grey literature search, only reports published by reputable organisations or peer-reviewed literature were included.

Eligibility criteria

We included studies that examined the impact of trauma, traumatic events or PTSD on social functioning in adult refugees and asylum seekers (aged 18 and above). We focused on both refugees and asylum seekers to understand trauma and social functioning within the context of displacement in a new host society. Papers were excluded if the participants lived in refugee camps as this setting is not within the post-migration context. Under 18s were excluded because often young people receive different support and may experience a different resettlement experience compared with adults. For example, it has been suggested that children and young people can better adapt to new environments, and school systems can promote resettlement. When it was unclear if the study was investigating the impact of trauma on social functioning (rather than the other way around) a detailed analysis of the full text was conducted. Studies were included if they used trauma-focused measures like the Harvard Trauma Questionnaire (HTQ), which assesses pre-migration traumas. However, if a PTSD measure was used the paper was assessed further to determine the directionality of the relationship. While PTSD can result from displacement experiences, research has shown it may also develop as a consequence of social functioning difficulties and acculturation challenges.

Given this bidirectional relationship we only included studies that investigated how PTSD symptoms predicted social functioning outcomes. However, we excluded studies that primarily examined how social functioning predicted PTSD outcomes, even if they initially presented correlational analyses between these variables.A study was also excluded if it was published in any language other than English, or if it was not primary peer-reviewed research (e.g. dissertations, case studies or series, literature reviews and systematic reviews). Within the grey literature search, reports published by reputable organisations or peer-reviewed literature were included. We excluded dissertations, as although they undergo some level of review, the extent to which each chapter has been thoroughly assessed cannot be assured. Finally, we excluded studies published more than 30 years ago. This date limitation accounts for the impact of globalisation and digitalisation on integration patterns and social functioning in modern host societies.

Screening, data extraction and analysis

The screening process utilised a two-stage procedure. Title and abstracts were initially screened by the first author (A.P.) using Rayyan. Two authors (A.P., J.M.) then independently screened the full-texts, and any discrepancies were discussed (κ = 0.473, moderate agreement). A third author (I.M.) was approached for papers where the two authors could not reach a consensus. All references were reviewed, and those meeting the inclusion criteria were incorporated. We applied the same process for the grey literature search. Following this, data were extracted on the study design, methodology, sample size and characteristics, measures (trauma, PTSD, social functioning), trauma type, social functioning factors and the results between trauma or PTSD and social functioning (19 December 2024). We contacted authors when data were missing or incongruent. One author (A.P.) completed this phase, with the second author (J.M.) checking the information. Microsoft Excel (version 16.99.2) was used to extract the data. The data was analysed to identify key themes using a narrative synthesis. To further stratify by trauma type we identified and analysed studies which focused on specific trauma exposures, exploring associations with, or impacts on, differing social functioning outcomes.

Analysis of bias

We assessed the quality of each paper using the Mixed Methods Appraisal Tool (MMAT) (see Appendix B in the Supplementary material). Two authors independently rated each study against the criterion, with any discrepancies discussed. For any difficulties in reaching a consensus, another team member was consulted. We do not provide an overall risk of bias score, but instead present a qualitative description of the studies’ quality in the results, as recommended. For grey literature that did not fit into the MMAT grouping, we used the Authority, Accuracy, Coverage, Objectivity, Date, Significance (AACODS) risk of bias tool.

Results

We identified 1388 references from the search, after removing duplicates. Following the title and abstract screening, 70 full texts were screened for eligibility, of which, 33 met the criteria. A further five studies were identified from the references and grey literature, resulting in a total of 38 studies (see Fig. 1).

Study characteristics

Studies included were published between 1998 and 2024, with varied designs (see Supplementary Table 1 available at https://doi.org/10.1192/bjp.2025.10385): mixed methods (n = 1), cross-sectional (n = 21), longitudinal (n = 8), randomised control trial data (n = 1), secondary data analysis (n = 1) and qualitative studies (n= 6). The research spanned multiple countries: Australia (n = 10), Austria (n = 3), Germany (n = 4), Israel (n = 2), Jordan (n = 1), Norway (n = 1), Serbia (n = 1), Sweden (n = 1), Switzerland (n = 2), Turkey (n = 2), Uganda (n = 1), UK (n = 2), USA (n = 7) and a European collection of countries (n = 1). In total, 15 394 participants were included, representing diverse populations. Samples involved displaced populations who were Congolese (n = 1), Vietnamese (n = 2), Syrian (n= 4), Somali (n = 1), Eritrean (n = 2) Afghan (n = 5), Cambodian (n = 2), Bosnian (n = 1), Yugoslavian (n = 1) and of mixed nationalities (n = 19). Reasons for leaving their homes and specific traumatic events included: war and/or conflict (n = 2), persecution under oppressive systems targeting LGBTQIA + individuals (n = 1), violence and abuse (n = 1), a lack of basic needs (n = 1), being close to death (n = 1), individual (n = 1), family (n = 1) and collective trauma (n = 1), trafficking/torture (n = 3), separated and not separated from family (n= 1), genocide (n = 1), and others reported traumatic events more generally (n = 24).

Risk of bias

We carefully evaluated all papers for potential bias, using the MMAT for 37 papers and AACODS for one non-peer-reviewed paper (see Appendix B in the Supplementary material). The risk of bias highlights some key areas where the findings should be interpreted with caution. Many quantitative studies clearly defined their inclusion and exclusion criteria, but ten papers lacked clarity in this regard or failed to report these details. Thirty-three papers acknowledged the limited generalisability of their findings. This limitation was often due to the use of convenience or snowball sampling methods, or a focus on specific target populations – such as individuals who were from a particular country, highly educated, technology proficient or married. One research team conducted a structural equation model, while acknowledging their study did not have sufficient statistical power. Two other papers did not provide information on the validity of their measurement tools. Meanwhile, five papers had incomplete outcome data, or it was difficult to determine their completeness, although all papers did control for confounders. One descriptive paper appeared to be at risk for non-response bias.All qualitative research studies showed minimal bias, while the sole mixed-methods paper fell short of certain criteria. It lacked a clear rationale for using mixed methods and failed to effectively integrate both quantitative and qualitative results. Lastly, the one grey literature paper reviewed met all the AACODS grading criteria.

Themes

Five key social functioning themes arose out of the literature, these were: post-migration living difficulties, everyday functioning, acculturation and integration, social relationships, and employment and education (see Supplementary Table 1).

Post-migration living difficulties

Eight studies reported on the impact of trauma on post-displacement living difficulties (PMLDs), i.e. learning a new language, loneliness, discrimination and access to support). The research consistently linked PTSD and traumatic experiences to heightened PMLDs.

Specifically, trauma significantly predicted worries about the future, including visa insecurity and emergency return concerns. A latent class analysis (LCA) provided support for this result, showing that individuals facing severe PMLDs had experienced more traumatic events than those in moderate or low-PMLD groups. Only one study found no association between the total number of traumatic events and the total number of PMLDs.

Everyday functioning

Five studies explored how trauma affects everyday functioning, with mixed results. Ainamani et al. identified a significant positive correlation between PTSD and psychosocial dysfunction. Qualitative data highlighted several underlying mechanisms, including shame-induced low mood leading to self-neglect, post-trauma physical health challenges and a progressively negative self-perception. Other studies failed to find a relationship between traumatic experiences and daily functioning or between trauma and help-seeking.

Acculturation and integration

Evidence of the impact of trauma on integration and acculturation in a host country was mixed. Nine studies demonstrated negative effects on integration. Trauma severity correlated with increased acculturation difficulties. Trauma was further associated with reduced sociocultural adaptation, as well as diminished ethnic and host cultural orientation and adoption, and reduced cultural competency. This relationship can be mediated by emotion-focused coping, negative contacts with host country civilians and acculturative stress. Individuals with PTSD symptoms showed similar patterns – with reduced social integration and difficulties with language acquisition in those with complex PTSD cluster.

However, recent studies revealed more nuanced relationships between trauma and integration. Using structural equation modelling, Kurt et al found that traumatic events negatively predict heritage culture maintenance while positively predicting destination culture adoption, even though initial bivariate correlations had suggested no relationship with host culture adoption. Limited effects were observed in relation to trauma on societal participation, except when individuals experienced violence and abuse, which significantly impaired participation.

Conversely, eight studies reported minimal or no effects of trauma on acculturation outcomes. Traumatic events were found to have no association with acculturation, integration in Norwegian culture and orientation toward host or origin culture, nor did they predict cultural identity or English language competency. While Hunkler and Khourshed reported an effect of traumatic events on cognitive-cultural integration, this effect was not significant. Regarding community engagement, PTSD symptoms at a first measurement timepoint did not predict later engagement. Additionally, no differences were observed in socioeconomic conditions, discrimination, family concerns or residence insecurity in those with complex PTSD compared with those with standard PTSD.

Social relationships

Eighteen studies presented mixed findings in relation to the impact of trauma on social relationships, with the majority of studies reporting a negative effect of trauma on positive social relationships. In one study, over 70% of participants with PTSD reported social withdrawal and inactivity. Additionally, in an LCA, participants allocated to a social disconnection group had experienced a greater variety of traumatic events compared with other groups (i.e. fear of immigration, low/moderate difficulties classes). Trauma was linked with weaker social networks and predicted fewer contacts with the host society, through the impact on mental health symptoms.

Trauma further predicted more post-migration living difficulties related to isolation and loneliness, predicting subsequent depression, PTSD and disability. Increased post-traumatic cognitions were associated with less social connectedness, although more traumatised individuals still yearned for social contact. Eritrean participants further reported the negative impacts of trauma on relationships with both fellow Eritreans and Israelis.

The role of mistrust, leading to isolation and strained relationships was highlighted in the qualitative research. Specifically, trafficking survivors reported that their perpetrators were often friends which compounded the loss of trust. Others felt shame about their traumatic experiences, contributing to their isolation. Additionally, challenges in sharing their experiences arose due to a lack of empathy or understanding from others. Injuries from torture caused shame in social settings while trauma-induced insomnia made social interactions more difficult. Other difficulties that arose as a result of the trauma included fear of commitment, heightened aggression and obsessive behaviours – all of which influenced their relationships with others.

Our analysis indicated that trauma has a negative impact on family relationships. Over 50% of refugees and asylum seekers reported avoiding social contact due to unfulfilled family expectations following experiences of trauma. Participants identifying as LGBTQIA+ distanced themselves from family members, viewing their family as part of the oppressive system. Some respondents hesitated to share their experiences, both to protect their loved ones from hearing about their torture and out of fear of criticism. In some cases, family members held participants responsible for their detention, contributing to a fractured relationship. Traumatic events also predicted more worries for family members in their home country or in detention, and others felt family life was unachievable.

Nevertheless, some positive outcomes of trauma exposure were also reported, including greater family unity, stronger emotional bonds and enhanced interpersonal understanding. Those who were survivors of a genocide found the trauma increased their compassion, with a greater sense of interconnectedness. The positive effect of experiencing trauma extended to their family members where they had a new sense of appreciation. Other research found that trauma can have a positive impact on the support they received from their spouse. This positive effect extended past family connections with analyses showing that group membership was 1.08 times higher for each point increase in trauma exposure.

Notably, however, three studies found no relationship between trauma and social engagement or social network size. However, ongoing PTSD was associated with a weak social network. Another study found that while traumatic events prior to resettlement were negatively associated with social support, adding trauma to their predictive model did not improve its explanatory power.

Employment and education

Fifteen studies investigated the impact of trauma on employment or education. Although the majority of studies indicated the negative effects of trauma on employment, some results were mixed. In one study, over 50% described avoiding stressful situations such as searching for a job following rejection. In addition, those experiencing PTSD often had lower employment opportunities or trauma was associated with unemployment. Participants expressed not feeling mentally well-enough to work, and others felt they had lost hope and trauma had led to a negative view of the world, where employment did not seem possible.

When in work, task-oriented performance was affected in individuals suffering from PTSD (i.e. work that demonstrates problem solving, coping with stress and learning). Longitudinally, traumatic experiences negatively predicted employment status, labour income, labour force participation, permanent job status, skilled occupation, hours worked a week and work in agriculture. Traumatic events additionally predicted economic post-migration living difficulties, which were then related to increased depressive symptoms. Additional results supported the findings of negative impacts.

Trauma following torture led to difficulties in committing to work. For others, it motivated them to engage in activism for their home country, shifting priorities away from employment in the host country. However, in some cases post-traumatic growth is possible, with a direct effect on adaptive performance: handling stress and emergencies, creative problem-solving, interpersonal adaptability, coping with unpredictable work environments and learning new tasks. For instance, Cambodian leaders who were displaced in the USA used their trauma as a strength. Participants felt that trauma shifted their priorities and goals, inspiring a new dedication to higher education or career advancement. Being in the USA provided additional opportunities, fostering a belief that nothing is impossible and giving participants a renewed sense of purpose. Some embraced new missions, pursuing meaning through political activism, community engagement or helping others. In trafficked survivors, trauma resulted in a drive to create a better future, with a focus on education and careers which help others. Despite this, five studies found that traumatic events had no effect on employment or education.

Stratification by traumatic events

Eleven papers focused on specific traumatic events which can be grouped into interpersonal and war-based trauma.

Interpersonal trauma

Eight studies explored the impact of interpersonal trauma on social functioning, with many focusing specifically on the link with social relationships. Survivors of abuse, trafficking or torture experienced greater integration issues and impaired participation. Participation challenges were specifically related to a lack of engagement in community activities. Integration was further limited, measured by a subsection of the PMLD checklist encompassing difficulties around communication, social participation, access to services, everyday living and discrimination. Trauma resulted in isolation, loneliness and struggles with trust, shame, aggression and strained relationships. LGBTQIA+ individuals viewed family as part of an oppressive system, affecting their relationships, though some trauma survivors reported stronger family bonds and a greater emotional understanding. Interpersonal trauma also affected additional areas of social functioning. Collective trauma symptoms were linked to post-migration difficulties, and family separation was associated with increased social, economic and future-related challenges. However, growth was evident in some, with a desire for educational and employment opportunities. Cambodian genocide survivors, for example, reshaped their life goals towards education, careers or activism, finding renewed purpose in the USA. Having been close to death or experiencing a lack of basic needs was not related to participation.

War-based trauma

Three papers focused on conflict-based trauma. One study found that a model including gender, age and education predicted 7% of the variance in psychosocial dysfunction. However, when war- or conflict-related PTSD was added, the model’s predictive value increased to 48%. Higher levels of PTSD following war were also associated with greater self-reported integration difficulties, yet the experience of war-related trauma and probable PTSD symptoms did not predict help-seeking.

Discussion

We identified five key themes relating to social functioning among trauma-affected displaced populations: post-migration living difficulties, everyday functioning, acculturation and integration, social relationships, and employment and education. While the existing literature offers a nuanced understanding of these themes, our review highlights that trauma predominately has a negative impact on social functioning. However, positive outcomes in relation to social functioning following trauma are possible.

Social functioning factors affected by trauma

The reviewed studies consistently showed a strong link between trauma and post-migration living difficulties. Most studies utilised the PMLD questionnaire, which encompasses factors such as communication barriers, discrimination, family separation, employment challenges, access to support, financial strain and social connectedness. Such difficulties are well-documented, with displaced individuals commonly experiencing many challenges throughout the post-migration period. Recent recommendations have suggested that clinicians and policy-makers should consider providing multifaceted, integrated support. This should involve practical aid with housing, employment, the asylum process and skills-based training. Given that trauma can exacerbate these difficulties further, clinicians should also consider broader factors in relation to supporting trauma recovery. Services must further ensure that displaced individuals, especially those with trauma histories, are not further disadvantaged and that barriers (i.e. language) to access are mitigated.

The effects of trauma on everyday psychosocial functioning, acculturation and integration were mixed, with reports of varying to no effects. Regarding everyday functioning, these findings both align with and contradict the broader literature on PTSD in the general population, which consistently reports significant impairments in daily functioning with large effect sizes.

In terms of acculturation, the wider literature suggests psychological acculturation (i.e. identification with the host culture) is multifaceted and impacted by social support, education, school-based factors in host countries, and academic achievement. The mixed findings therefore underscore the complexity of some social functioning factors. These contradictory findings may also be explained by the convenience samples used in the majority of the reviewed studies that are effective at targeting hard-to-reach populations, but may consist of participants who function better in everyday life. Future research is needed to examine the effects of trauma on everyday functioning in displaced groups further.Social relationships were predominately negatively impacted by trauma, particularly through mechanisms of social withdrawal, perceived stigma, mistrust, and isolation. These findings are reflected in the broader scope of literature exploring social connectedness within displaced populations. For example, a systematic review found the loneliness (15.9–47.7%) and social isolation (9.8–61.2%) rates in refugee populations are higher than in the general population. Trauma’s role in disconnection extends beyond refugee contexts, as childhood trauma has been linked to social exclusion in adulthood, and PTSD symptoms are shown to have a bidirectional relationship with loneliness.

Trust was an additional mechanism that is disrupted as a result of trauma, leading to subsequent issues with relationships. This theme is prominent in the literature, where refugees face distinct trust challenges, and those who have experienced interpersonal trauma demonstrate a reduced capacity to trust others – with a need to rebuild trust following resettlement. Therefore strategies fostering trust could play a critical role in breaking the cycle of trauma and social disconnection. This aligns with the socio-interpersonal view of PTSD. The framework proposes that trauma affects three layers: (a) social affects (i.e. guilt, shame, social withdrawal), (b) social connection (i.e. social support), and (c) culture and society (i.e. cultural values). The impacts on such areas can perpetuate PTSD severity, in line with a previous meta-analysis which found that social support is negatively related to PTSD severity. Drawing on existing theoretical frameworks, prior research, and the present findings, clinicians and intervention programmes should prioritise social factors and actively facilitate the rebuilding of social connections.

Notably, some participants displayed a newfound appreciation for their family, and increased compassion and interconnectedness following trauma. This may represent a growing phenomenon recognised in the literature as ‘post-traumatic growth’, the idea that there is potential for growth following adversity, and that some find benefit in stressful events. Post-traumatic growth has also been reported in displaced populations during resettlement, with factors such as high educational attainment and religious commitment being associated with more post-traumatic growth. Sultani, Heinsch further reported on increased post-traumatic growth in those with a drive to help and serve the community which could explain why Cambodian leaders demonstrated a positive response to trauma.Growth was also present within the context of employment. For some displaced people, trauma catalysed positive shifts in goals and values, fostering a renewed sense of purpose. This emphasises the importance of post-traumatic growth and the need to promote hope, resilience and empowerment during recovery and in seeking sanctuary. Clinicians therefore need to support resilience building as suggested by the socio-interpersonal framework, focusing on both trauma and broader social factors in intervention. Future research should explore how interventions can be tailored to enhance post-traumatic growth, particularly in displaced populations.

Trauma stratification

We identified two trauma-focused themes: interpersonal trauma and war-related trauma. While these events may not be mutually exclusive, the results suggested differing outcomes for those primarily affected by war, and those affected by torture. War-based trauma predominantly affected psychosocial functioning and integration, while interpersonal trauma was more disruptive of social relationships. Both themes shared a common impact on social factors, but the influence was notably more pronounced in individuals who experienced interpersonal trauma.Additional research has found social cooperation and trust to be diminished in individuals who have experienced interpersonal trauma. Therefore, interpersonal trauma may fragment attachment systems and have a more deep-rooted impact on individuals’ ability to engage in, and maintain, positive social interactions. This may be because experiences of torture, trafficking, abuse, or ostracism often involve betrayal, which fundamentally undermines trust and can result in avoidant attachment styles. Models of PTSD in displaced populations have suggested such changes to attachment can perpetuate PTSD symptoms. This underscores the importance of addressing social factors in clinical interventions and policy planning. On the other hand, war-related trauma, while similarly affecting social factors, tends to manifest more in broader societal concerns, as supported by studies on veterans. This highlights the importance of considering trauma type when providing interventions and support plans to displaced groups.

Critical appraisal

A key strength of our review is that it is the first to systematically synthesise the literature on trauma and its impact on social functioning in displaced groups who have resettled. By consolidating the evidence across studies, it provides a comprehensive framework for understanding the intersection of trauma and social functioning. Furthermore, by combining insights from a diverse range of studies, including cross-sectional, longitudinal, mixed-methods, and qualitative, our review paints a nuanced picture of how trauma can impact social functioning in displaced groups. This included grey literature and one report, aiming to provide a broader representation of the literature and reduce the reliance on Western or Global North sources. However, we acknowledge that the exclusion of dissertations or non-English papers may have limited the representativeness of the sample.

We note some further methodological limitations. First, only one author screened the titles and abstracts. Given the full-text screening showed only moderate agreement between two authors, the breadth of the initial screening stage may have been limited. Of the studies included, several relied on snowball or convenience sampling. While some authors stated that these samples were representative of the target population, such approaches may overlook individuals at the pointiest end of trauma exposure and those who may experience more profound functional impairment. Such populations are often hard to engage, even under optimal conditions, and their exclusion likely limits the scope and generalisability of the findings. Consequently, this sampling bias may partially explain instances where the relationship between trauma and social functioning was inconsistent.

We also did not explore the differences between complex PTSD and PTSD which may have differential social functioning outcomes, especially given complex PTSD often presents following an interpersonal trauma. For example, non-displaced populations with complex PTSD show pronounced difficulties with interpersonal relationships compared with their PTSD counterparts. Therefore, future research should consider focusing on complex PTSD or distinguishing between the two conditions, as this may reveal important differences in social outcomes and inform more targeted interventions.

Another limitation is that only eight longitudinal studies were included. While these studies provide valuable insights into causality and the long-term impacts of trauma, more longitudinal research is needed to capture the evolving nature of post-migration living difficulties over time. Most studies further relied on semi-structured interviews or questionnaires. Future research could explore alternative design, such as experimental or creative visual methods, to examine aspects of social functioning affected by trauma that may be overlooked in standard surveys. Despite these limitations, our review highlights several critical implications. It underscores the pressing need for trauma-informed interventions tailored to address the compounded challenges faced by displaced populations, alongside emphasising the importance of societal efforts to promote integration, reduce systemic barriers, and foster post-traumatic growth in displaced groups.

Implications and future directions

In summary, while trauma often leads to social functioning challenges, the literature also highlights instances of resilience and post-traumatic growth. However, additional research is needed to better understand the effects of specific trauma types and to adopt alternative research methods, such as visual creative approaches, which may better capture lived experiences. Furthermore, cultural, social (e.g. refugee status), and personal factors (e.g. age, gender) require deeper exploration to understand how they interact with trauma in shaping social functioning and overall well-being in displaced populations. These intersecting influences are crucial for developing context-sensitive interventions.Nevertheless, our findings suggest that the effects of trauma are not homogeneous, and interventions should be tailored to the individual’s experiences, while facilitating post-traumatic growth. Policy makers should recognise the importance of social systems which has been extensively supported across the literature and with a range of perspectives. Clinicians should further consider broader social factors when supporting trauma. Overall, the review calls for more holistic support in relation to trauma in refugees and asylum seekers. In doing so, interventions can promote growth and improve social functioning at an individual level but can more broadly improve integration and cohesion in society.

Summary

Globally, 117.3 million individuals were displaced by the end of 2023. This number includes 68.3 million people displaced within their own countries, 43.5 million refugees, and 6.9 million asylum seekers. Experts predict this figure could rise to 1.2 billion by 2050, partly due to climate change. A refugee is someone who has fled their country due to danger and cannot return. An asylum seeker has left their country and formally applied for international protection, but their request is still being reviewed. Displacement occurs due to various reasons, such as conflicts, violence, human rights abuses, personal or group identities, and forced military service. While official ways to seek safety exist (like resettlement programs), many displaced individuals must leave their countries through unofficial routes.

Trauma is a common experience for displaced people, occurring both during the displacement process and during resettlement. Trauma related to displacement can be broken down into three stages: pre-migration (before leaving home), peri-migration (the journey to safety), and post-migration (resettlement in a new country). Each stage presents unique challenges and potential for traumatic experiences. Research shows that during these periods, individuals often face traumatic events such as war, violence, lack of basic necessities, family separation, and poor living conditions.

This trauma often leads to high rates of mental health issues, especially post-traumatic stress disorder (PTSD), affecting 31.5–43% of displaced individuals. For the general population, trauma can significantly impact quality of life, emotional and behavioral functioning, and both physical and mental health.

Displaced individuals experience similar outcomes from trauma, including increased rates of PTSD, depression, anxiety, and difficulty integrating into new communities. Some studies also report problems with memory and executive function, along with a higher risk of developing other mental health conditions like psychosis.

Social Functioning

Trauma and PTSD can also affect social functioning in the general population. Social functioning refers to how individuals interact within society and their personal lives. More specifically, it describes how a person engages with their environment and their ability to fulfill roles in work, social activities, and relationships with partners and family. This ability is vital for displaced groups to successfully integrate into a new country. Those who integrate well tend to thrive and contribute to a healthy society. Suggestions for improving integration for displaced people include better housing, employment, language support, education, social inclusion, avoiding detention, and proactive management of physical and mental health.

However, trauma deeply impacts an individual's ability to function in a new society. Given how common trauma is in this population, understanding integration and social functioning in the context of displacement is crucial. While research exists on the effects of trauma or PTSD on social functioning, the findings are not always consistent. Some studies show a significant negative impact of trauma on various aspects of functioning in displaced groups, while others suggest the possibility of improvement after trauma. Although individual studies have looked at different parts of social functioning, no review has yet combined how trauma or PTSD influences different areas of social functioning after migration.

Study Aims

Due to the inconsistent findings in existing research, a systematic approach is needed to clarify the relationship between trauma, PTSD, and social functioning in refugees and asylum seekers after migration. The goal was to systematically review the literature to determine how trauma and PTSD affect social functioning in adult displaced groups. Specifically, the study aimed to identify which aspects of social functioning are most affected by trauma and analyze how different types of traumatic events influence these key areas.

Method

This systematic review followed PRISMA guidelines, and its protocol was submitted to PROSPERO (CRD42024612834).

Search

The search strategy was developed by conducting initial searches of current literature and identifying key terms for the PICO (Participant, Intervention, Comparator, Outcome) framework. Searches were performed between November 2024 and February 2025 in EMBASE, MEDLINE, PsycINFO, Scopus, and Web of Science databases. Grey literature was also searched on government websites, the United Nations, the World Health Organization, Amnesty International, Freedom from Torture, Hestia, and Helen Bamber. Only reports from reputable organizations or peer-reviewed literature found within the grey literature search were included.

Eligibility Criteria

Studies examining the impact of trauma, traumatic events, or PTSD on social functioning in adult refugees and asylum seekers (age 18 and older) were included. The focus included both refugees and asylum seekers to understand trauma and social functioning in the context of displacement in a new host society. Papers were excluded if participants lived in refugee camps, as this setting does not fit the post-migration context. Individuals under 18 were excluded because young people often receive different support and may have a different resettlement experience compared to adults. For example, it has been suggested that children and young people adapt better to new environments, and school systems can aid resettlement. When it was unclear whether a study investigated the impact of trauma on social functioning (rather than the reverse), a detailed analysis of the full text was conducted. Studies were included if they used trauma-focused measures like the Harvard Trauma Questionnaire (HTQ), which assesses pre-migration traumas. However, if a PTSD measure was used, the paper was further assessed to determine the direction of the relationship. While PTSD can result from displacement experiences, research shows it may also develop as a consequence of social functioning difficulties and challenges with adapting to a new culture.

Given this two-way relationship, only studies that investigated how PTSD symptoms predicted social functioning outcomes were included. However, studies primarily examining how social functioning predicted PTSD outcomes were excluded, even if they initially presented analyses showing a correlation between these variables. Studies published in languages other than English or those that were not primary peer-reviewed research (e.g., dissertations, case studies or series, literature reviews, and systematic reviews) were also excluded. Within the grey literature search, only reports published by reputable organizations or peer-reviewed literature were included. Dissertations were excluded because, although they undergo some review, the thoroughness of assessment for each chapter cannot be guaranteed. Finally, studies published more than 30 years ago were excluded. This date limitation accounts for the impact of globalization and digitalization on integration patterns and social functioning in modern host societies.

Screening, Data Extraction and Analysis

The screening process involved two stages. First, titles and abstracts were screened by the primary author (A.P.) using Rayyan. Then, two authors (A.P., J.M.) independently screened the full texts, and any disagreements were discussed (κ = 0.473, moderate agreement). A third author (I.M.) was consulted for papers where the two authors could not agree. All references were reviewed, and those meeting the inclusion criteria were incorporated. The same process was applied to the grey literature search. Following this, data on study design, methodology, sample size and characteristics, measures (trauma, PTSD, social functioning), trauma type, social functioning factors, and the results between trauma or PTSD and social functioning were extracted (December 19, 2024). Authors were contacted when data were missing or inconsistent. One author (A.P.) completed this phase, with a second author (J.M.) checking the information. Microsoft Excel (version 16.99.2) was used for data extraction. The data were analyzed to identify key themes using a narrative synthesis. To further categorize by trauma type, studies focusing on specific trauma exposures were identified and analyzed, exploring their associations with or impacts on different social functioning outcomes.

Analysis of Bias

The quality of each paper was assessed using the Mixed Methods Appraisal Tool (MMAT). Two authors independently rated each study against the criteria, discussing any differences. If a consensus could not be reached, another team member was consulted. An overall risk of bias score is not provided; instead, a qualitative description of the studies’ quality is presented in the results, as recommended. For grey literature that did not fit the MMAT categories, the Authority, Accuracy, Coverage, Objectivity, Date, Significance (AACODS) risk of bias tool was used.

Results

After removing duplicates, 1388 references were identified from the search. Following the title and abstract screening, 70 full texts were reviewed for eligibility, of which 33 met the criteria. An additional five studies were identified from references and grey literature, resulting in a total of 38 studies.

Study Characteristics

The included studies were published between 1998 and 2024 and featured various designs: one mixed-methods study, 21 cross-sectional studies, eight longitudinal studies, one study using randomized control trial data, one secondary data analysis, and six qualitative studies. Research was conducted in multiple countries: Australia (10 studies), Austria (3), Germany (4), Israel (2), Jordan (1), Norway (1), Serbia (1), Sweden (1), Switzerland (2), Turkey (2), Uganda (1), UK (2), USA (7), and a collection of European countries (1). In total, 15,394 participants were included, representing diverse populations. Samples involved displaced individuals who were Congolese (1 study), Vietnamese (2), Syrian (4), Somali (1), Eritrean (2), Afghan (5), Cambodian (2), Bosnian (1), Yugoslavian (1), and of mixed nationalities (19). Reasons for leaving home and specific traumatic events included: war and/or conflict (2 studies), persecution under oppressive systems targeting LGBTQIA+ individuals (1), violence and abuse (1), lack of basic needs (1), being close to death (1), individual (1), family (1) and collective trauma (1), trafficking/torture (3), separated and not separated from family (1), genocide (1), and others reported traumatic events more generally (24).

Risk of Bias

All papers were carefully evaluated for potential bias, using the MMAT for 37 papers and AACODS for one non-peer-reviewed paper. The risk of bias highlights key areas where findings should be interpreted with caution. Many quantitative studies clearly defined their inclusion and exclusion criteria, but ten papers lacked clarity or failed to report these details. Thirty-three papers acknowledged the limited generalizability of their findings, often due to the use of convenience or snowball sampling methods, or a focus on specific populations (e.g., from a particular country, highly educated, technologically proficient, or married). One research team conducted a structural equation model, while acknowledging their study lacked sufficient statistical power. Two other papers did not provide information on the validity of their measurement tools. Meanwhile, five papers had incomplete outcome data, or its completeness was difficult to determine, although all papers did control for confounders. One descriptive paper appeared at risk for non-response bias. All qualitative research studies showed minimal bias, while the sole mixed-methods paper fell short of certain criteria. It lacked a clear reason for using mixed methods and failed to effectively combine quantitative and qualitative results. Lastly, the one grey literature paper reviewed met all the AACODS grading criteria.

Themes

Five key themes related to social functioning emerged from the literature: post-migration living difficulties, everyday functioning, acculturation and integration, social relationships, and employment and education.

Post-Migration Living Difficulties

Eight studies reported on how trauma impacts post-displacement living difficulties (PMLDs), which include challenges like learning a new language, loneliness, discrimination, and access to support. The research consistently linked PTSD and traumatic experiences to increased PMLDs. Specifically, trauma significantly predicted worries about the future, such as visa insecurity and concerns about emergency returns. A latent class analysis supported this, showing that individuals facing severe PMLDs had experienced more traumatic events than those in moderate or low-PMLD groups. Only one study found no connection between the total number of traumatic events and the total number of PMLDs.

Everyday Functioning

Five studies examined how trauma affects everyday functioning, with mixed results. Ainamani et al. found a significant positive correlation between PTSD and psychosocial dysfunction. Qualitative data revealed several underlying reasons, including shame-induced low mood leading to self-neglect, physical health problems after trauma, and a worsening negative self-perception. Other studies did not find a relationship between traumatic experiences and daily functioning or between trauma and seeking help.

Acculturation and Integration

Evidence on the impact of trauma on integration and acculturation in a host country was mixed. Nine studies showed negative effects on integration. The severity of trauma correlated with increased difficulties in acculturation. Trauma was also linked to reduced sociocultural adaptation, as well as diminished identification with and adoption of both ethnic and host cultures, and reduced cultural competence. This relationship can be influenced by emotion-focused coping strategies, negative interactions with host country citizens, and stress related to adapting to a new culture. Individuals with PTSD symptoms showed similar patterns, with reduced social integration and difficulties learning the language, particularly in those with complex PTSD.

However, recent studies revealed more complex relationships between trauma and integration. Using structural equation modeling, Kurt et al. found that traumatic events negatively predicted the maintenance of heritage culture while positively predicting the adoption of the destination culture, even though initial simple correlations had suggested no relationship with host culture adoption. Limited effects were observed regarding trauma on participation in society, except when individuals experienced violence and abuse, which significantly impaired participation.

Conversely, eight studies reported minimal or no effects of trauma on acculturation outcomes. Traumatic events were found to have no association with acculturation, integration into Norwegian culture, or orientation towards host or origin culture, nor did they predict cultural identity or English language proficiency. While Hunkler and Khourshed reported an effect of traumatic events on cognitive-cultural integration, this effect was not significant. Regarding community engagement, PTSD symptoms at an initial measurement point did not predict later engagement. Additionally, no differences were observed in socioeconomic conditions, discrimination, family concerns, or residence insecurity in those with complex PTSD compared with those with standard PTSD.

Social Relationships

Eighteen studies presented mixed findings regarding the impact of trauma on social relationships, with most studies reporting a negative effect of trauma on positive social relationships. In one study, over 70% of participants with PTSD reported social withdrawal and inactivity. Additionally, in a latent class analysis, participants categorized into a social disconnection group had experienced a greater variety of traumatic events compared with other groups (e.g., fear of immigration, low/moderate difficulties classes). Trauma was linked to weaker social networks and predicted fewer contacts with the host society, due to its impact on mental health symptoms.

Trauma further predicted more post-migration living difficulties related to isolation and loneliness, which in turn predicted subsequent depression, PTSD, and disability. Increased post-traumatic thoughts were associated with less social connectedness, although more traumatized individuals still desired social contact. Eritrean participants also reported the negative impacts of trauma on relationships with both fellow Eritreans and Israelis.

Qualitative research highlighted the role of mistrust, leading to isolation and strained relationships. Specifically, trafficking survivors reported that their perpetrators were often friends, which worsened the loss of trust. Others felt shame about their traumatic experiences, contributing to their isolation. Additionally, challenges in sharing their experiences arose due to a lack of empathy or understanding from others. Injuries from torture caused shame in social settings, while trauma-induced insomnia made social interactions more difficult. Other difficulties resulting from trauma included fear of commitment, heightened aggression, and obsessive behaviors—all of which influenced their relationships with others.

Analysis indicated that trauma negatively impacts family relationships. Over 50% of refugees and asylum seekers reported avoiding social contact due to unfulfilled family expectations following traumatic experiences. Participants identifying as LGBTQIA+ distanced themselves from family members, viewing their family as part of an oppressive system. Some respondents hesitated to share their experiences, both to protect loved ones from hearing about their torture and out of fear of criticism. In some cases, family members held participants responsible for their detention, contributing to fractured relationships. Traumatic events also predicted more worries for family members in their home country or in detention, and others felt family life was unachievable.

Nevertheless, some positive outcomes of trauma exposure were also reported, including greater family unity, stronger emotional bonds, and enhanced interpersonal understanding. Those who were survivors of genocide found that trauma increased their compassion, with a greater sense of interconnectedness. The positive effect of experiencing trauma extended to their family members, where they developed a new sense of appreciation. Other research found that trauma can have a positive impact on the support received from a spouse. This positive effect extended beyond family connections, with analyses showing that group membership was 1.08 times higher for each point increase in trauma exposure.

Notably, however, three studies found no relationship between trauma and social engagement or social network size. However, ongoing PTSD was associated with a weak social network. Another study found that while traumatic events prior to resettlement were negatively associated with social support, adding trauma to their predictive model did not improve its explanatory power.

Employment and Education

Fifteen studies examined the impact of trauma on employment or education. Although most studies indicated negative effects of trauma on employment, some results were mixed. In one study, over 50% described avoiding stressful situations, such as job searching after rejection. Additionally, those experiencing PTSD often had fewer employment opportunities, or trauma was associated with unemployment. Participants expressed not feeling mentally well enough to work, and others felt they had lost hope, with trauma leading to a negative view of the world where employment seemed impossible.

When employed, task-oriented performance was affected in individuals suffering from PTSD (e.g., work involving problem-solving, coping with stress, and learning). Over time, traumatic experiences negatively predicted employment status, labor income, labor force participation, permanent job status, skilled occupation, hours worked per week, and work in agriculture. Traumatic events also predicted economic post-migration living difficulties, which were then linked to increased depressive symptoms. Additional results supported the findings of negative impacts.

Trauma following torture led to difficulties in committing to work. For others, it motivated them to engage in activism for their home country, shifting priorities away from employment in the host country. However, in some cases, post-traumatic growth is possible, with a direct effect on adaptive performance: handling stress and emergencies, creative problem-solving, interpersonal adaptability, coping with unpredictable work environments, and learning new tasks. For instance, Cambodian leaders displaced in the USA used their trauma as a strength. Participants felt that trauma shifted their priorities and goals, inspiring a new dedication to higher education or career advancement. Being in the USA provided additional opportunities, fostering a belief that nothing is impossible and giving participants a renewed sense of purpose. Some embraced new missions, pursuing meaning through political activism, community engagement, or helping others. In trafficked survivors, trauma resulted in a drive to create a better future, with a focus on education and careers that help others. Despite this, five studies found that traumatic events had no effect on employment or education.

Stratification by Traumatic Events

Eleven papers focused on specific traumatic events, which can be grouped into interpersonal and war-based trauma.

Interpersonal Trauma

Eight studies explored the impact of interpersonal trauma on social functioning, with many focusing specifically on its link with social relationships. Survivors of abuse, trafficking, or torture experienced greater integration issues and impaired participation. Participation challenges were specifically related to a lack of engagement in community activities. Integration was further limited, measured by a subsection of the PMLD checklist encompassing difficulties with communication, social participation, access to services, everyday living, and discrimination. Trauma resulted in isolation, loneliness, and struggles with trust, shame, aggression, and strained relationships. LGBTQIA+ individuals viewed family as part of an oppressive system, affecting their relationships, though some trauma survivors reported stronger family bonds and greater emotional understanding. Interpersonal trauma also affected additional areas of social functioning. Collective trauma symptoms were linked to post-migration difficulties, and family separation was associated with increased social, economic, and future-related challenges. However, growth was evident in some, with a desire for educational and employment opportunities. Cambodian genocide survivors, for example, reshaped their life goals toward education, careers, or activism, finding renewed purpose in the USA. Having been close to death or experiencing a lack of basic needs was not related to participation.

War-Based Trauma

Three papers focused on conflict-based trauma. One study found that a model including gender, age, and education predicted 7% of the variation in psychosocial dysfunction. However, when war- or conflict-related PTSD was added, the model’s predictive value increased to 48%. Higher levels of PTSD following war were also associated with greater self-reported integration difficulties, yet the experience of war-related trauma and probable PTSD symptoms did not predict help-seeking.

Discussion

Five key themes related to social functioning among trauma-affected displaced populations were identified: post-migration living difficulties, everyday functioning, acculturation and integration, social relationships, and employment and education. While existing literature offers a detailed understanding of these themes, this review highlights that trauma primarily has a negative impact on social functioning. However, positive outcomes in social functioning following trauma are also possible.

Social Functioning Factors Affected by Trauma

The studies reviewed consistently showed a strong link between trauma and post-migration living difficulties. Most studies used the PMLD questionnaire, which covers factors such as communication barriers, discrimination, family separation, employment challenges, access to support, financial strain, and social connectedness. These difficulties are well-documented, with displaced individuals commonly experiencing many challenges throughout the post-migration period. Recent recommendations suggest that clinicians and policymakers should consider providing multifaceted, integrated support. This should involve practical aid with housing, employment, the asylum process, and skills-based training. Given that trauma can worsen these difficulties, clinicians should also consider broader factors in supporting trauma recovery. Services must also ensure that displaced individuals, especially those with a history of trauma, are not further disadvantaged and that barriers (e.g., language) to access are reduced.

The effects of trauma on everyday psychosocial functioning, acculturation, and integration were mixed, with reports ranging from varying to no effects. Regarding everyday functioning, these findings both align with and contradict the broader literature on PTSD in the general population, which consistently reports significant impairments in daily functioning with large effect sizes. In terms of acculturation, broader literature suggests that psychological acculturation (i.e., identifying with the host culture) is complex and influenced by social support, education, school-based factors in host countries, and academic achievement. The mixed findings therefore highlight the complexity of some social functioning factors. These contradictory findings may also be explained by the use of convenience samples in most reviewed studies, which are effective at reaching hard-to-access populations but may consist of participants who function better in everyday life. Future research is needed to further examine the effects of trauma on everyday functioning in displaced groups.

Social relationships were predominantly negatively impacted by trauma, particularly through mechanisms of social withdrawal, perceived stigma, mistrust, and isolation. These findings are consistent with broader literature exploring social connectedness within displaced populations. For example, a systematic review found that rates of loneliness (15.9–47.7%) and social isolation (9.8–61.2%) in refugee populations are higher than in the general population. Trauma’s role in disconnection extends beyond refugee contexts, as childhood trauma has been linked to social exclusion in adulthood, and PTSD symptoms are shown to have a two-way relationship with loneliness.

Trust was another mechanism disrupted by trauma, leading to subsequent relationship issues. This theme is prominent in the literature, where refugees face distinct trust challenges, and those who have experienced interpersonal trauma show a reduced capacity to trust others—with a need to rebuild trust following resettlement. Therefore, strategies that foster trust could play a critical role in breaking the cycle of trauma and social disconnection. This aligns with the socio-interpersonal view of PTSD. This framework suggests that trauma affects three layers: (a) social emotions (e.g., guilt, shame, social withdrawal), (b) social connection (e.g., social support), and (c) culture and society (e.g., cultural values). The impacts on these areas can worsen PTSD severity, consistent with a previous meta-analysis that found social support is negatively related to PTSD severity. Drawing on existing theoretical frameworks, prior research, and the current findings, clinicians and intervention programs should prioritize social factors and actively facilitate the rebuilding of social connections.

Notably, some participants displayed a newfound appreciation for their family and increased compassion and interconnectedness following trauma. This may represent a growing phenomenon recognized in the literature as ‘post-traumatic growth,’ the idea that there is potential for growth following adversity and that some find benefit in stressful events. Post-traumatic growth has also been reported in displaced populations during resettlement, with factors such as high educational attainment and religious commitment associated with more post-traumatic growth. Sultani, Heinsch further reported increased post-traumatic growth in those with a drive to help and serve the community, which could explain why Cambodian leaders demonstrated a positive response to trauma. Growth was also present within the context of employment. For some displaced people, trauma catalyzed positive shifts in goals and values, fostering a renewed sense of purpose. This emphasizes the importance of post-traumatic growth and the need to promote hope, resilience, and empowerment during recovery and in seeking sanctuary. Clinicians therefore need to support resilience building as suggested by the socio-interpersonal framework, focusing on both trauma and broader social factors in intervention. Future research should explore how interventions can be tailored to enhance post-traumatic growth, particularly in displaced populations.

Trauma Stratification

Two trauma-focused themes were identified: interpersonal trauma and war-related trauma. While these events may not be entirely separate, the results suggested different outcomes for those primarily affected by war versus those affected by torture. War-based trauma predominantly affected psychosocial functioning and integration, while interpersonal trauma was more disruptive to social relationships. Both themes shared a common impact on social factors, but the influence was notably more pronounced in individuals who experienced interpersonal trauma. Additional research has found social cooperation and trust to be diminished in individuals who have experienced interpersonal trauma. Therefore, interpersonal trauma may fragment attachment systems and have a more deep-rooted impact on individuals’ ability to engage in and maintain positive social interactions. This may be because experiences of torture, trafficking, abuse, or ostracism often involve betrayal, which fundamentally undermines trust and can result in avoidant attachment styles. Models of PTSD in displaced populations have suggested such changes to attachment can perpetuate PTSD symptoms. This underscores the importance of addressing social factors in clinical interventions and policy planning. On the other hand, war-related trauma, while similarly affecting social factors, tends to manifest more in broader societal concerns, as supported by studies on veterans. This highlights the importance of considering trauma type when providing interventions and support plans to displaced groups.

Critical Appraisal

A key strength of this review is that it is the first to systematically combine literature on trauma and its impact on social functioning in displaced groups who have resettled. By consolidating evidence across studies, it provides a comprehensive framework for understanding the intersection of trauma and social functioning. Furthermore, by combining insights from a diverse range of studies, including cross-sectional, longitudinal, mixed-methods, and qualitative, this review offers a nuanced picture of how trauma can impact social functioning in displaced groups. This included grey literature and one report, aiming to provide a broader representation of the literature and reduce reliance on Western or Global North sources. However, it is acknowledged that excluding dissertations or non-English papers may have limited the representativeness of the sample.

Some additional methodological limitations are noted. First, only one author screened the titles and abstracts. Given that the full-text screening showed only moderate agreement between two authors, the thoroughness of the initial screening stage may have been limited. Among the included studies, several relied on snowball or convenience sampling. While some authors stated that these samples were representative of the target population, such approaches may overlook individuals most severely affected by trauma and those who may experience more profound functional impairment. Such populations are often difficult to engage, even under ideal conditions, and their exclusion likely limits the scope and generalizability of the findings. Consequently, this sampling bias may partly explain instances where the relationship between trauma and social functioning was inconsistent.

The review also did not explore the differences between complex PTSD and PTSD, which may have different social functioning outcomes, especially given that complex PTSD often results from interpersonal trauma. For example, non-displaced populations with complex PTSD show pronounced difficulties with interpersonal relationships compared with those with standard PTSD. Therefore, future research should consider focusing on complex PTSD or distinguishing between the two conditions, as this may reveal important differences in social outcomes and inform more targeted interventions.

Another limitation is that only eight longitudinal studies were included. While these studies provide valuable insights into causality and the long-term impacts of trauma, more longitudinal research is needed to capture the evolving nature of post-migration living difficulties over time. Most studies also relied on semi-structured interviews or questionnaires. Future research could explore alternative designs, such as experimental or creative visual methods, to examine aspects of social functioning affected by trauma that may be overlooked in standard surveys. Despite these limitations, this review highlights several critical implications. It underscores the urgent need for trauma-informed interventions tailored to address the compounded challenges faced by displaced populations, while also emphasizing the importance of societal efforts to promote integration, reduce systemic barriers, and foster post-traumatic growth in displaced groups.

Implications and Future Directions

In summary, while trauma often leads to challenges in social functioning, the literature also highlights instances of resilience and post-traumatic growth. However, more research is needed to better understand the effects of specific trauma types and to adopt alternative research methods, such as visual creative approaches, which may better capture lived experiences. Furthermore, cultural, social (e.g., refugee status), and personal factors (e.g., age, gender) require deeper exploration to understand how they interact with trauma in shaping social functioning and overall well-being in displaced populations. These intersecting influences are crucial for developing interventions that are sensitive to context. Nevertheless, these findings suggest that the effects of trauma are not uniform, and interventions should be tailored to individual experiences while facilitating post-traumatic growth. Policymakers should recognize the importance of social systems, which has been extensively supported across the literature and from various perspectives. Clinicians should also consider broader social factors when supporting trauma. Overall, the review calls for more holistic support for trauma in refugees and asylum seekers. In doing so, interventions can promote growth and improve social functioning at an individual level, and more broadly improve integration and cohesion in society.

Summary

At the end of 2023, 117.3 million people were displaced globally. This includes 68.3 million people displaced within their own countries, 43.5 million refugees, and 6.9 million asylum seekers. Experts predict these numbers could reach 1.2 billion by 2050, partly due to climate change. A refugee is someone who has left their country and cannot safely return. An asylum seeker has formally applied for protection in another country, but their application is still being reviewed. Displacement occurs due to various reasons, such as conflicts, violence, human rights abuses, identity-based persecution, and forced military service. While some official pathways exist for seeking safety, many displaced individuals must leave their countries through unofficial routes.

Trauma is a common experience for displaced individuals, arising from the displacement process itself and the challenges of settling into a new place. Trauma can occur during three main periods: before leaving home (pre-migration), during the journey to safety (peri-migration), and after settling in a new country (post-migration). Each stage presents unique challenges and potential for traumatic experiences. Studies have shown that individuals often face traumatic events such as war, violence, lack of basic necessities, family separation, and poor living conditions during these periods.

This trauma is evident in high rates of mental health issues, particularly post-traumatic stress disorder (PTSD), which affects 31.5–43% of displaced individuals. In the general population, trauma can significantly impact a person's quality of life, their ability to function emotionally and behaviorally, and their physical and mental health.

For displaced individuals, trauma leads to similar outcomes, including increased rates of PTSD, depression, anxiety, and a reduced ability to integrate into new communities. Some research also indicates cognitive problems affecting memory and executive function, as well as a higher risk of developing other mental health conditions like psychosis.

Social Functioning

Trauma and PTSD can also affect social functioning in the general population. Social functioning refers to how individuals interact within society and their personal surroundings.

More specifically, social functioning describes an individual's engagement with their environment and their ability to fulfill roles in work, social activities, and relationships with partners and family. This ability is crucial for displaced groups to successfully integrate into a host country. Successful integration, in turn, helps individuals thrive and contributes to a healthy society. Suggestions for improving integration for displaced people include better housing options, employment, language support and education, social inclusion, avoiding detention, and proactive management of physical and mental health issues.

However, trauma significantly impairs a person's ability to function in a new society. Given the high rates of trauma in this population, understanding integration and social functioning in the context of displacement is essential. While research exists on how trauma or PTSD affects social functioning, the findings are inconsistent. Some studies highlight a strong negative impact of trauma on various aspects of functioning in displaced groups, while others suggest the possibility of improvement after trauma. Although individual studies have explored different aspects of social functioning, no single review has yet summarized how trauma or PTSD influences various areas of social functioning after migration.

Study Aims

Due to the inconsistent findings in existing research, a systematic approach is necessary to clarify the relationship between trauma, PTSD, and social functioning in refugees and asylum seekers after migration. The goal was to systematically review the literature to determine how trauma and PTSD affect social functioning in adult displaced groups. Specifically, the study aimed to identify the aspects of social functioning most affected by trauma and to analyze how different types of traumatic events influence these key areas.

Method

The systematic review followed PRISMA guidelines, and a protocol was submitted to PROSPERO (CRD42024612834).

Search

A search strategy was developed using initial searches of current literature and key terms applied to the PICO (Participant, Intervention, Comparator, Outcome) framework (see Appendix A in the Supplementary material). Searches were conducted between November 2024 and February 2025 in EMBASE, MEDLINE, PsycINFO, Scopus, and Web of Science databases. Grey literature was searched on government websites, the United Nations, the World Health Organization, Amnesty International, Freedom from Torture, Hestia, and Helen Bamber. Only reports published by reputable organizations or peer-reviewed literature were included from the grey literature search.

Eligibility Criteria

Studies examining the impact of trauma, traumatic events, or PTSD on social functioning in adult refugees and asylum seekers (aged 18 and above) were included. The focus was on both refugees and asylum seekers to understand trauma and social functioning in the context of displacement in a new host society. Papers were excluded if participants lived in refugee camps, as this setting does not represent the post-migration context. Individuals under 18 were excluded because young people often receive different support and may have a different resettlement experience compared to adults. For example, some suggest that children and young people adapt better to new environments, and school systems can aid resettlement. If it was unclear whether a study investigated the impact of trauma on social functioning (rather than the reverse), a detailed analysis of the full text was performed. Studies were included if they used trauma-focused measures, such as the Harvard Trauma Questionnaire (HTQ), which assesses pre-migration traumas. However, if a PTSD measure was used, the paper was further evaluated to determine the direction of the relationship. While PTSD can result from displacement, research shows it can also develop from difficulties in social functioning and challenges with acculturation.

Given this two-way relationship, only studies investigating how PTSD symptoms predicted social functioning outcomes were included. However, studies primarily examining how social functioning predicted PTSD outcomes were excluded, even if they initially presented correlational analyses between these variables. Studies published in languages other than English or those not considered primary peer-reviewed research (e.g., dissertations, case studies or series, literature reviews, and systematic reviews) were also excluded. Within the grey literature search, reports published by reputable organizations or peer-reviewed literature were included. Dissertations were excluded because, although they undergo some review, the extent to which each chapter has been thoroughly assessed cannot be guaranteed. Finally, studies published more than 30 years ago were excluded to account for the impact of globalization and digitalization on integration patterns and social functioning in modern host societies.

Screening, Data Extraction and Analysis

The screening process involved two stages. Titles and abstracts were initially screened by the first author (A.P.) using Rayyan. Two authors (A.P., J.M.) then independently screened the full texts, and any disagreements were discussed (κ = 0.473, moderate agreement). A third author (I.M.) was consulted for papers where the two authors could not reach a consensus. All references were reviewed, and those meeting the inclusion criteria were incorporated. The same process was applied to the grey literature search. Following this, data on study design, methodology, sample size and characteristics, measures (trauma, PTSD, social functioning), trauma type, social functioning factors, and the results between trauma or PTSD and social functioning were extracted (December 19, 2024). Authors were contacted if data were missing or inconsistent. One author (A.P.) completed this phase, with the second author (J.M.) checking the information. Microsoft Excel (version 16.99.2) was used to extract the data. The data were analyzed using a narrative synthesis to identify key themes. To further categorize by trauma type, studies focusing on specific trauma exposures were identified and analyzed, exploring their associations with or impacts on different social functioning outcomes.

Analysis of Bias

The quality of each paper was assessed using the Mixed Methods Appraisal Tool (MMAT) (see Appendix B in the Supplementary material). Two authors independently rated each study against the criteria, discussing any discrepancies. If consensus was difficult to reach, another team member was consulted. An overall risk of bias score was not provided; instead, a qualitative description of the studies' quality is presented in the results, as recommended. For grey literature that did not fit the MMAT grouping, the Authority, Accuracy, Coverage, Objectivity, Date, Significance (AACODS) risk of bias tool was used.

Results

After removing duplicates, 1388 references were identified from the search. Following title and abstract screening, 70 full texts were screened for eligibility, with 33 meeting the criteria. An additional five studies were identified from references and grey literature, resulting in a total of 38 studies (see Fig. 1).

Study Characteristics

The included studies were published between 1998 and 2024 and featured various designs (see Supplementary Table 1 available at https://doi.org/10.1192/bjp.2025.10385): mixed methods (n = 1), cross-sectional (n = 21), longitudinal (n = 8), randomized control trial data (n = 1), secondary data analysis (n = 1), and qualitative studies (n = 6). The research spanned multiple countries: Australia (n = 10), Austria (n = 3), Germany (n = 4), Israel (n = 2), Jordan (n = 1), Norway (n = 1), Serbia (n = 1), Sweden (n = 1), Switzerland (n = 2), Turkey (n = 2), Uganda (n = 1), UK (n = 2), USA (n = 7), and a European collection of countries (n = 1). In total, 15,394 participants were included, representing diverse populations. Samples included displaced populations who were Congolese (n = 1), Vietnamese (n = 2), Syrian (n = 4), Somali (n = 1), Eritrean (n = 2), Afghan (n = 5), Cambodian (n = 2), Bosnian (n = 1), Yugoslavian (n = 1), and of mixed nationalities (n = 19). Reasons for leaving their homes and specific traumatic events included: war and/or conflict (n = 2), persecution under oppressive systems targeting LGBTQIA+ individuals (n = 1), violence and abuse (n = 1), a lack of basic needs (n = 1), being close to death (n = 1), individual (n = 1), family (n = 1) and collective trauma (n = 1), trafficking/torture (n = 3), separated and not separated from family (n = 1), genocide (n = 1), and others reported traumatic events more generally (n = 24).

Risk of Bias

All papers were carefully evaluated for potential bias, using the MMAT for 37 papers and AACODS for one non-peer-reviewed paper (see Appendix B in the Supplementary material). The risk of bias highlights some key areas where the findings should be interpreted with caution. Many quantitative studies clearly defined their inclusion and exclusion criteria, but ten papers lacked clarity in this regard or failed to report these details. Thirty-three papers acknowledged the limited generalizability of their findings. This limitation was often due to the use of convenience or snowball sampling methods, or a focus on specific target populations – such as individuals from a particular country, highly educated, technologically proficient, or married. One research team conducted a structural equation model while acknowledging their study did not have sufficient statistical power. Two other papers did not provide information on the validity of their measurement tools. Meanwhile, five papers had incomplete outcome data, or it was difficult to determine their completeness, although all papers did control for confounders. One descriptive paper appeared to be at risk for non-response bias. All qualitative research studies showed minimal bias, while the sole mixed-methods paper fell short of certain criteria. It lacked a clear rationale for using mixed methods and failed to effectively integrate both quantitative and qualitative results. Lastly, the one grey literature paper reviewed met all the AACODS grading criteria.

Themes

Five key social functioning themes emerged from the literature: post-migration living difficulties, everyday functioning, acculturation and integration, social relationships, and employment and education (see Supplementary Table 1).

Post-Migration Living Difficulties

Eight studies reported on how trauma affects post-displacement living difficulties (PMLDs), such as learning a new language, loneliness, discrimination, and access to support. The research consistently linked PTSD and traumatic experiences to increased PMLDs.

Specifically, trauma significantly predicted worries about the future, including concerns about visa insecurity and emergency return. A latent class analysis (LCA) supported this finding, showing that individuals facing severe PMLDs had experienced more traumatic events than those in moderate or low-PMLD groups. Only one study found no association between the total number of traumatic events and the total number of PMLDs.

Everyday Functioning

Five studies explored how trauma affects everyday functioning, with mixed results. Ainamani et al. found a significant positive correlation between PTSD and psychosocial dysfunction. Qualitative data highlighted several underlying reasons, including shame-induced low mood leading to self-neglect, physical health challenges after trauma, and a progressively negative self-perception. Other studies did not find a relationship between traumatic experiences and daily functioning or between trauma and seeking help.

Acculturation and Integration

Evidence on the impact of trauma on integration and acculturation in a host country was mixed. Nine studies showed negative effects on integration. The severity of trauma correlated with increased difficulties in acculturation. Trauma was also linked to reduced sociocultural adaptation, decreased identification with and adoption of both ethnic and host cultures, and reduced cultural competence. This relationship can be influenced by emotion-focused coping, negative interactions with host country civilians, and acculturative stress. Individuals with PTSD symptoms showed similar patterns, with reduced social integration and difficulties in language acquisition for those with complex PTSD.

However, recent studies revealed more complex relationships between trauma and integration. Using structural equation modeling, Kurt et al. found that traumatic events negatively predicted maintaining one's heritage culture while positively predicting adopting the destination culture, even though initial simple correlations showed no relationship with host culture adoption. Limited effects were observed regarding trauma on participation in society, except when individuals experienced violence and abuse, which significantly impaired participation.

Conversely, eight studies reported minimal or no effects of trauma on acculturation outcomes. Traumatic events were found to have no association with acculturation, integration into Norwegian culture, or orientation toward host or origin culture. They also did not predict cultural identity or English language proficiency. While Hunkler and Khourshed reported an effect of traumatic events on cognitive-cultural integration, this effect was not significant. Regarding community engagement, PTSD symptoms at an initial measurement point did not predict later engagement. Additionally, no differences were observed in socioeconomic conditions, discrimination, family concerns, or housing insecurity in those with complex PTSD compared to those with standard PTSD.

Social Relationships

Eighteen studies presented mixed findings regarding the impact of trauma on social relationships, with most studies reporting a negative effect of trauma on positive social relationships. In one study, over 70% of participants with PTSD reported social withdrawal and inactivity. Additionally, in an LCA, participants assigned to a social disconnection group had experienced a greater variety of traumatic events compared to other groups (e.g., fear of immigration, low/moderate difficulties classes). Trauma was linked with weaker social networks and predicted fewer contacts with the host society through its impact on mental health symptoms.

Trauma further predicted more post-migration living difficulties related to isolation and loneliness, which predicted subsequent depression, PTSD, and disability. Increased post-traumatic thoughts were associated with less social connectedness, although more traumatized individuals still desired social contact. Eritrean participants also reported the negative impacts of trauma on relationships with both fellow Eritreans and Israelis.

Qualitative research highlighted the role of mistrust, leading to isolation and strained relationships. Specifically, trafficking survivors reported that their perpetrators were often friends, which compounded the loss of trust. Others felt shame about their traumatic experiences, contributing to their isolation. Additionally, challenges in sharing their experiences arose due to a lack of empathy or understanding from others. Injuries from torture caused shame in social settings, while trauma-induced insomnia made social interactions more difficult. Other difficulties resulting from trauma included fear of commitment, heightened aggression, and obsessive behaviors – all of which influenced their relationships with others.

The analysis indicated that trauma negatively impacts family relationships. Over 50% of refugees and asylum seekers reported avoiding social contact due to unfulfilled family expectations following experiences of trauma. Participants identifying as LGBTQIA+ distanced themselves from family members, viewing their family as part of an oppressive system. Some respondents hesitated to share their experiences, both to protect their loved ones from hearing about their torture and out of fear of criticism. In some cases, family members held participants responsible for their detention, contributing to a fractured relationship. Traumatic events also predicted more worries for family members in their home country or in detention, and others felt family life was unachievable.

Nevertheless, some positive outcomes of trauma exposure were also reported, including greater family unity, stronger emotional bonds, and enhanced interpersonal understanding. Those who were survivors of a genocide found that trauma increased their compassion and a greater sense of interconnectedness. The positive effect of experiencing trauma extended to their family members, where they had a new sense of appreciation. Other research found that trauma can have a positive impact on the support received from a spouse. This positive effect extended beyond family connections, with analyses showing that group membership was 1.08 times higher for each point increase in trauma exposure.

Notably, however, three studies found no relationship between trauma and social engagement or social network size. However, ongoing PTSD was associated with a weak social network. Another study found that while traumatic events prior to resettlement were negatively associated with social support, adding trauma to their predictive model did not improve its explanatory power.

Employment and Education

Fifteen studies investigated the impact of trauma on employment or education. Although most studies indicated the negative effects of trauma on employment, some results were mixed. In one study, over 50% described avoiding stressful situations such as searching for a job after rejection. Additionally, those experiencing PTSD often had fewer employment opportunities, or trauma was associated with unemployment. Participants expressed not feeling mentally well enough to work, and others felt they had lost hope, with trauma leading to a negative view of the world where employment seemed impossible.

When employed, task-oriented performance was affected in individuals suffering from PTSD (e.g., work that demonstrates problem-solving, coping with stress, and learning). Longitudinally, traumatic experiences negatively predicted employment status, labor income, labor force participation, permanent job status, skilled occupation, hours worked per week, and work in agriculture. Traumatic events also predicted economic post-migration living difficulties, which were then related to increased depressive symptoms. Additional results supported the findings of negative impacts.

Trauma following torture led to difficulties in committing to work. For others, it motivated them to engage in activism for their home country, shifting priorities away from employment in the host country. However, in some cases, post-traumatic growth is possible, with a direct effect on adaptive performance: handling stress and emergencies, creative problem-solving, interpersonal adaptability, coping with unpredictable work environments, and learning new tasks. For instance, Cambodian leaders displaced in the USA used their trauma as a strength. Participants felt that trauma shifted their priorities and goals, inspiring a new dedication to higher education or career advancement. Being in the USA provided additional opportunities, fostering a belief that nothing is impossible and giving participants a renewed sense of purpose. Some embraced new missions, pursuing meaning through political activism, community engagement, or helping others. In trafficked survivors, trauma resulted in a drive to create a better future, with a focus on education and careers that help others. Despite this, five studies found that traumatic events had no effect on employment or education.

Stratification by Traumatic Events

Eleven papers focused on specific traumatic events, which can be grouped into interpersonal and war-based trauma.

Interpersonal Trauma

Eight studies explored the impact of interpersonal trauma on social functioning, with many focusing specifically on its link with social relationships. Survivors of abuse, trafficking, or torture experienced greater integration issues and impaired participation. Participation challenges were specifically related to a lack of engagement in community activities. Integration was further limited, as measured by a subsection of the PMLD checklist encompassing difficulties with communication, social participation, access to services, everyday living, and discrimination. Trauma resulted in isolation, loneliness, and struggles with trust, shame, aggression, and strained relationships. LGBTQIA+ individuals viewed family as part of an oppressive system, affecting their relationships, though some trauma survivors reported stronger family bonds and greater emotional understanding. Interpersonal trauma also affected additional areas of social functioning. Collective trauma symptoms were linked to post-migration difficulties, and family separation was associated with increased social, economic, and future-related challenges. However, growth was evident in some, with a desire for educational and employment opportunities. Cambodian genocide survivors, for example, reshaped their life goals toward education, careers, or activism, finding renewed purpose in the USA. Having been close to death or experiencing a lack of basic needs was not related to participation.

War-Based Trauma

Three papers focused on conflict-based trauma. One study found that a model including gender, age, and education predicted 7% of the variation in psychosocial dysfunction. However, when war- or conflict-related PTSD was added, the model’s predictive value increased to 48%. Higher levels of PTSD following war were also associated with greater self-reported integration difficulties, yet the experience of war-related trauma and probable PTSD symptoms did not predict help-seeking.

Discussion

Five key social functioning themes were identified among trauma-affected displaced populations: post-migration living difficulties, everyday functioning, acculturation and integration, social relationships, and employment and education. While the existing literature offers a detailed understanding of these themes, this review highlights that trauma predominantly negatively impacts social functioning. However, positive outcomes related to social functioning following trauma are possible.

Social Functioning Factors Affected by Trauma

The reviewed studies consistently showed a strong link between trauma and post-migration living difficulties. Most studies used the PMLD questionnaire, which covers factors such as communication barriers, discrimination, family separation, employment challenges, access to support, financial strain, and social connectedness. These difficulties are well-documented, with displaced individuals commonly experiencing many challenges during the post-migration period. Recent recommendations suggest that clinicians and policymakers should consider providing multifaceted, integrated support. This should involve practical aid with housing, employment, the asylum process, and skills-based training. Given that trauma can further exacerbate these difficulties, clinicians should also consider broader factors in supporting trauma recovery. Services must also ensure that displaced individuals, especially those with trauma histories, are not further disadvantaged and that barriers (e.g., language) to access are reduced.

The effects of trauma on everyday psychosocial functioning, acculturation, and integration were mixed, with reports ranging from varying to no effects. Regarding everyday functioning, these findings both align with and contradict the broader literature on PTSD in the general population, which consistently reports significant impairments in daily functioning with large effect sizes.

In terms of acculturation, the wider literature suggests that psychological acculturation (e.g., identification with the host culture) is complex and influenced by social support, education, school-based factors in host countries, and academic achievement. The mixed findings therefore highlight the complexity of some social functioning factors. These contradictory findings may also be explained by the convenience samples used in most reviewed studies, which are effective at reaching hard-to-access populations but may include participants who function better in daily life. Future research is needed to further examine the effects of trauma on everyday functioning in displaced groups.

Social relationships were predominantly negatively impacted by trauma, particularly through social withdrawal, perceived stigma, mistrust, and isolation. These findings are consistent with broader literature exploring social connectedness in displaced populations. For example, a systematic review found that rates of loneliness (15.9–47.7%) and social isolation (9.8–61.2%) in refugee populations are higher than in the general population. Trauma's role in disconnection extends beyond refugee contexts, as childhood trauma has been linked to social exclusion in adulthood, and PTSD symptoms are shown to have a two-way relationship with loneliness.

Trust was another mechanism disrupted by trauma, leading to subsequent relationship issues. This theme is prominent in the literature, where refugees face distinct trust challenges, and those who have experienced interpersonal trauma show a reduced ability to trust others, requiring trust to be rebuilt after resettlement. Therefore, strategies that foster trust could play a critical role in breaking the cycle of trauma and social disconnection. This aligns with the socio-interpersonal view of PTSD. This framework suggests that trauma affects three layers: (a) social emotions (e.g., guilt, shame, social withdrawal), (b) social connection (e.g., social support), and (c) culture and society (e.g., cultural values). The impacts on these areas can worsen PTSD severity, consistent with a previous meta-analysis that found social support is negatively related to PTSD severity. Drawing on existing theoretical frameworks, prior research, and the present findings, clinicians and intervention programs should prioritize social factors and actively help rebuild social connections.

Notably, some participants showed a newfound appreciation for their family and increased compassion and interconnectedness after trauma. This may represent a growing phenomenon recognized in the literature as "post-traumatic growth," the idea that there is potential for growth after adversity and that some find benefits in stressful events. Post-traumatic growth has also been reported in displaced populations during resettlement, with factors such as high educational attainment and religious commitment associated with more post-traumatic growth. Sultani and Heinsch also reported increased post-traumatic growth in those with a drive to help and serve the community, which could explain why Cambodian leaders demonstrated a positive response to trauma.

Growth was also present within the context of employment. For some displaced people, trauma catalyzed positive shifts in goals and values, fostering a renewed sense of purpose. This emphasizes the importance of post-traumatic growth and the need to promote hope, resilience, and empowerment during recovery and when seeking sanctuary. Clinicians therefore need to support resilience building as suggested by the socio-interpersonal framework, focusing on both trauma and broader social factors in intervention. Future research should explore how interventions can be designed to enhance post-traumatic growth, particularly in displaced populations.

Trauma Stratification

Two trauma-focused themes were identified: interpersonal trauma and war-related trauma. While these events may not be mutually exclusive, the results suggested different outcomes for those primarily affected by war compared to those affected by torture. War-based trauma predominantly affected psychosocial functioning and integration, while interpersonal trauma was more disruptive to social relationships. Both themes shared a common impact on social factors, but the influence was notably more pronounced in individuals who experienced interpersonal trauma. Additional research has found social cooperation and trust to be diminished in individuals who have experienced interpersonal trauma. Therefore, interpersonal trauma may fragment attachment systems and have a more deeply rooted impact on individuals' ability to engage in and maintain positive social interactions. This may be because experiences of torture, trafficking, abuse, or ostracism often involve betrayal, which fundamentally undermines trust and can result in avoidant attachment styles. Models of PTSD in displaced populations have suggested such changes to attachment can perpetuate PTSD symptoms. This highlights the importance of addressing social factors in clinical interventions and policy planning. On the other hand, war-related trauma, while similarly affecting social factors, tends to manifest more in broader societal concerns, as supported by studies on veterans. This underscores the importance of considering trauma type when providing interventions and support plans to displaced groups.

Critical Appraisal

A key strength of this review is that it is the first to systematically synthesize the literature on trauma and its impact on social functioning in displaced groups who have resettled. By combining evidence from various studies, it provides a comprehensive framework for understanding the intersection of trauma and social functioning. Furthermore, by integrating insights from a diverse range of studies, including cross-sectional, longitudinal, mixed-methods, and qualitative, the review offers a nuanced picture of how trauma can impact social functioning in displaced groups. This included grey literature and one report, aiming to provide a broader representation of the literature and reduce reliance on Western or Global North sources. However, it is acknowledged that the exclusion of dissertations or non-English papers may have limited the representativeness of the sample.

Some further methodological limitations are noted. First, only one author screened the titles and abstracts. Given that full-text screening showed only moderate agreement between two authors, the scope of the initial screening stage may have been limited. Of the included studies, several relied on snowball or convenience sampling. While some authors stated that these samples were representative of the target population, such approaches may overlook individuals most severely affected by trauma and those who may experience more profound functional impairment. Such populations are often difficult to engage, even under optimal conditions, and their exclusion likely limits the scope and generalizability of the findings. Consequently, this sampling bias may partially explain instances where the relationship between trauma and social functioning was inconsistent.

Differences between complex PTSD and PTSD, which may have different social functioning outcomes, especially given that complex PTSD often follows interpersonal trauma, were not explored. For example, non-displaced populations with complex PTSD show pronounced difficulties with interpersonal relationships compared to those with PTSD. Therefore, future research should consider focusing on complex PTSD or distinguishing between the two conditions, as this may reveal important differences in social outcomes and inform more targeted interventions.

Another limitation is that only eight longitudinal studies were included. While these studies provide valuable insights into causality and the long-term impacts of trauma, more longitudinal research is needed to capture the evolving nature of post-migration living difficulties over time. Most studies also relied on semi-structured interviews or questionnaires. Future research could explore alternative designs, such as experimental or creative visual methods, to examine aspects of social functioning affected by trauma that may be overlooked in standard surveys. Despite these limitations, this review highlights several critical implications. It underscores the pressing need for trauma-informed interventions tailored to address the compounded challenges faced by displaced populations, while also emphasizing the importance of societal efforts to promote integration, reduce systemic barriers, and foster post-traumatic growth in displaced groups.

Implications and Future Directions

In summary, while trauma often leads to challenges in social functioning, the literature also highlights instances of resilience and post-traumatic growth. However, additional research is needed to better understand the effects of specific trauma types and to adopt alternative research methods, such as visual creative approaches, which may better capture lived experiences. Furthermore, cultural, social (e.g., refugee status), and personal factors (e.g., age, gender) require deeper exploration to understand how they interact with trauma in shaping social functioning and overall well-being in displaced populations. These intersecting influences are crucial for developing context-sensitive interventions. Nevertheless, the findings suggest that the effects of trauma are not uniform, and interventions should be tailored to individual experiences while facilitating post-traumatic growth. Policymakers should recognize the importance of social systems, which has been extensively supported across the literature and with a range of perspectives. Clinicians should further consider broader social factors when supporting trauma. Overall, the review calls for more holistic support concerning trauma in refugees and asylum seekers. By doing so, interventions can promote growth and improve social functioning at an individual level, and more broadly improve integration and cohesion in society.

Summary

Globally, 117.3 million people were displaced by the end of 2023. This number includes 68.3 million people displaced within their own countries, 43.5 million refugees, and 6.9 million asylum seekers. Experts predict this number could reach 1.2 billion by 2050, partly due to climate change. A refugee is someone who has left their country and cannot safely return. An asylum seeker has formally asked for protection in another country, but their request is still being reviewed. Many factors cause displacement, such as conflicts, violence, human rights abuses, and forced military service. While some official paths to safety exist, many displaced people must leave their countries unofficially.

Displaced individuals commonly experience trauma, which can occur during the process of leaving their home and during resettlement. Experts have identified three distinct periods when trauma can happen: before leaving their home country, during the journey to safety, and while settling into a new country. Each stage presents unique challenges and potential for traumatic experiences. Studies show that individuals face traumatic events like war, violence, lack of basic necessities, family separation, and poor living conditions during these periods.

This trauma often leads to high rates of mental health problems, especially post-traumatic stress disorder (PTSD), affecting 31.5% to 43% of displaced people. In the general population, trauma significantly impacts a person's quality of life, their emotional and behavioral functioning, and their physical and mental health.

For displaced individuals, trauma results in similar outcomes, such as higher rates of PTSD, depression, and anxiety. It also reduces their ability to integrate into new communities. Some research also points to problems with memory and decision-making, as well as an increased risk of developing other mental health conditions like psychosis.

Social Functioning

Trauma and PTSD can also affect social functioning in the general population. Social functioning refers to how individuals interact with society and their personal surroundings.

More specifically, social functioning describes a person's involvement with their environment and their ability to fulfill roles in work, social activities, and relationships with partners and family. This ability is vital for displaced groups to successfully integrate into a host country. Those who integrate better tend to thrive and contribute positively to society. To help displaced people integrate, recommendations include improving housing, employment, language support, education, social inclusion, avoiding detention, and proactively managing physical and mental health issues.

However, trauma significantly hinders a person's ability to function in a new society. Given how common trauma is among this population, understanding integration and social functioning in the context of displacement is crucial. While research exists on how trauma or PTSD affects social functioning, the findings are mixed. Some studies highlight the severe negative effects of trauma on various aspects of functioning in displaced groups, while others suggest that improvement is possible after trauma. Although individual studies have looked at different parts of social functioning, no review has yet combined how trauma or PTSD affects these different areas after migration.

Study Aims

Because existing research has inconsistent findings, a systematic approach is necessary to clarify the connection between trauma, PTSD, and social functioning in refugees and asylum seekers after migration. The goal was to systematically review the existing literature to determine how trauma and PTSD impact social functioning in adult displaced groups. Specifically, the study aimed to identify the aspects of social functioning most affected by trauma and analyze how different types of traumatic events influence these key areas.

Method

The systematic review followed PRISMA guidelines and submitted a protocol to PROSPERO (CRD42024612834).

Search

The search strategy was developed using initial searches of current literature, and key terms were applied to the PICO (Participant, Intervention, Comparator, Outcome) framework. Searches were conducted between November 2024 and February 2025 in EMBASE, MEDLINE, PsycINFO, Scopus, and Web of Science databases. Government websites, United Nations, the World Health Organization, Amnesty International, Freedom from Torture, Hestia, and Helen Bamber were searched for grey literature. Only reports published by reputable organizations or peer-reviewed literature were included from the grey literature.

Eligibility Criteria

Studies that examined how trauma, traumatic events, or PTSD affected social functioning in adult refugees and asylum seekers (age 18 and older) were included. The focus was on both refugees and asylum seekers to understand trauma and social functioning in a new host society. Papers were excluded if participants lived in refugee camps because this setting is not considered a post-migration context. Individuals under 18 were excluded because young people often receive different support and may have a different resettlement experience than adults. For example, it has been suggested that children and young people adapt better to new environments, and school systems can help with resettlement. If it was unclear whether a study investigated the impact of trauma on social functioning (rather than the other way around), a detailed analysis of the full text was performed. Studies were included if they used trauma-focused measures, such as the Harvard Trauma Questionnaire (HTQ), which assesses pre-migration traumas. However, if a PTSD measure was used, the paper was further assessed to determine the direction of the relationship. While PTSD can result from displacement experiences, research shows it can also develop due to social functioning difficulties and challenges with adapting to a new culture.

Because of this two-way relationship, only studies that investigated how PTSD symptoms predicted social functioning outcomes were included. However, studies that primarily examined how social functioning predicted PTSD outcomes were excluded, even if they initially presented correlational analyses between these variables. Studies published in languages other than English or those that were not primary peer-reviewed research (e.g., dissertations, case studies or series, literature reviews, and systematic reviews) were also excluded. Within the grey literature search, reports published by reputable organizations or peer-reviewed literature were included. Dissertations were excluded because, while they undergo some review, the thoroughness of assessment for each chapter cannot be guaranteed. Finally, studies published more than 30 years ago were excluded. This time limit accounts for how globalization and digitalization have affected integration patterns and social functioning in modern host societies.

Screening, Data Extraction and Analysis

The screening process involved two stages. First, the titles and abstracts were screened by the primary author (A.P.) using Rayyan. Then, two authors (A.P., J.M.) independently screened the full texts, and any disagreements were discussed (κ = 0.473, moderate agreement). A third author (I.M.) was consulted for papers where the two authors could not agree. All references were reviewed, and those meeting the inclusion criteria were included. The same process was applied for the grey literature search. After this, data on study design, methods, sample size and characteristics, measures (trauma, PTSD, social functioning), trauma type, social functioning factors, and the results between trauma or PTSD and social functioning were extracted (December 19, 2024). Authors were contacted if data was missing or inconsistent. One author (A.P.) completed this phase, with the second author (J.M.) checking the information. Microsoft Excel (version 16.99.2) was used to extract the data. The data was analyzed to identify key themes using a narrative synthesis. To further categorize by trauma type, studies focusing on specific trauma exposures were identified and analyzed, exploring their associations with, or impacts on, different social functioning outcomes.

Analysis of Bias

The quality of each paper was assessed using the Mixed Methods Appraisal Tool (MMAT). Two authors independently rated each study against the criteria, discussing any discrepancies. If reaching a consensus was difficult, another team member was consulted. An overall risk of bias score was not provided; instead, a qualitative description of the studies’ quality is presented in the results, as recommended. For grey literature that did not fit the MMAT grouping, the Authority, Accuracy, Coverage, Objectivity, Date, Significance (AACODS) risk of bias tool was used.

Results

After removing duplicates, 1388 references were identified from the search. Following the title and abstract screening, 70 full texts were screened for eligibility, and 33 met the criteria. An additional five studies were found from references and grey literature, resulting in a total of 38 studies.

Study Characteristics

The included studies were published between 1998 and 2024 and had various designs: one mixed-methods study, 21 cross-sectional studies, eight longitudinal studies, one randomized controlled trial, one secondary data analysis, and six qualitative studies. Research was conducted in multiple countries: Australia (10), Austria (3), Germany (4), Israel (2), Jordan (1), Norway (1), Serbia (1), Sweden (1), Switzerland (2), Turkey (2), Uganda (1), UK (2), USA (7), and one collection of European countries. In total, 15,394 participants from diverse populations were included. Samples involved displaced people from Congo (1), Vietnam (2), Syria (4), Somalia (1), Eritrea (2), Afghanistan (5), Cambodia (2), Bosnia (1), Yugoslavia (1), and mixed nationalities (19). Reasons for leaving home and specific traumatic events included: war and/or conflict (2), persecution of LGBTQIA+ individuals (1), violence and abuse (1), lack of basic needs (1), near-death experiences (1), individual (1), family (1) and collective trauma (1), trafficking/torture (3), separation from family (1), genocide (1), and general reports of traumatic events (24).

Risk of Bias

All papers were carefully evaluated for potential bias using the MMAT for 37 papers and AACODS for one non-peer-reviewed paper. The risk of bias highlights key areas where findings should be interpreted cautiously. Many quantitative studies clearly defined their inclusion and exclusion criteria, but ten papers lacked clarity or failed to report these details. Thirty-three papers acknowledged the limited ability to apply their findings to a broader population. This limitation was often due to using convenience or snowball sampling methods, or focusing on specific groups, such as individuals from a particular country, highly educated people, those skilled with technology, or married individuals. One research team used a structural equation model but noted their study lacked sufficient statistical power. Two other papers did not provide information on the validity of their measurement tools. Meanwhile, five papers had incomplete outcome data, or its completeness was difficult to determine, although all papers controlled for confounding factors. One descriptive paper appeared at risk for non-response bias.

All qualitative research studies showed minimal bias, while the single mixed-methods paper did not meet certain criteria. It lacked a clear reason for using mixed methods and failed to effectively combine quantitative and qualitative results. Finally, the one grey literature paper reviewed met all the AACODS grading criteria.

Themes

Five main themes related to social functioning emerged from the literature: post-migration living difficulties, everyday functioning, cultural adaptation and integration, social relationships, and employment and education.

Post-Migration Living Difficulties

Eight studies reported on how trauma affects post-displacement living difficulties (PMLDs), such as learning a new language, loneliness, discrimination, and accessing support. Research consistently linked PTSD and traumatic experiences to increased PMLDs.

Specifically, trauma was a significant predictor of worries about the future, including visa insecurity and concerns about emergency return. A latent class analysis (LCA) supported this, showing that individuals with severe PMLDs had experienced more traumatic events than those with moderate or low PMLDs. Only one study found no connection between the total number of traumatic events and the total number of PMLDs.

Everyday Functioning

Five studies examined how trauma affects everyday functioning, with mixed results. Ainamani et al. found a significant positive link between PTSD and psychosocial dysfunction. Qualitative data revealed several underlying reasons, including shame-induced low mood leading to self-neglect, physical health issues after trauma, and a worsening negative self-perception. Other studies did not find a relationship between traumatic experiences and daily functioning, or between trauma and seeking help.

Acculturation and Integration

Evidence regarding trauma's impact on integration and acculturation in a host country was mixed. Nine studies showed negative effects on integration. The severity of trauma correlated with increased difficulties in adapting to a new culture. Trauma was also linked to reduced sociocultural adaptation, less engagement with both their ethnic and the host culture, and reduced cultural competence. This relationship can be influenced by emotion-focused coping, negative interactions with people from the host country, and stress related to cultural adaptation. Individuals with PTSD symptoms showed similar patterns, experiencing reduced social integration and difficulties learning the language, especially those with complex PTSD.

However, recent studies found more complex relationships between trauma and integration. Using structural equation modeling, Kurt et al. discovered that traumatic events negatively predicted maintaining one's heritage culture while positively predicting adopting the destination culture, even though initial comparisons showed no link with host culture adoption. Limited effects were observed between trauma and societal participation, except when individuals experienced violence and abuse, which significantly hindered participation.

Conversely, eight studies reported minimal or no effects of trauma on cultural adaptation outcomes. Traumatic events were found to have no association with acculturation, integration into Norwegian culture, or orientation towards host or origin culture, nor did they predict cultural identity or English language proficiency. While Hunkler and Khourshed reported an effect of traumatic events on cognitive-cultural integration, this effect was not significant. Regarding community engagement, PTSD symptoms measured at an earlier point did not predict later engagement. Additionally, no differences were observed in socioeconomic conditions, discrimination, family concerns, or housing insecurity between those with complex PTSD and those with standard PTSD.

Social Relationships

Eighteen studies presented mixed findings regarding the impact of trauma on social relationships, with most studies reporting a negative effect of trauma on positive social relationships. In one study, over 70% of participants with PTSD reported social withdrawal and inactivity. Additionally, in an LCA, participants in a social disconnection group had experienced a greater variety of traumatic events compared to other groups (e.g., fear of immigration, low/moderate difficulties classes). Trauma was linked to weaker social networks and predicted fewer contacts with the host society, due to its impact on mental health symptoms.

Trauma further predicted more post-migration living difficulties related to isolation and loneliness, which then predicted subsequent depression, PTSD, and disability. Increased post-traumatic thoughts were associated with less social connection, although more traumatized individuals still desired social contact. Eritrean participants also reported the negative impacts of trauma on relationships with both fellow Eritreans and Israelis.

Qualitative research highlighted the role of mistrust, which led to isolation and strained relationships. Specifically, trafficking survivors reported that their attackers were often friends, which worsened the loss of trust. Others felt shame about their traumatic experiences, contributing to their isolation. Additionally, challenges in sharing their experiences arose due to a lack of empathy or understanding from others. Injuries from torture caused shame in social settings, while trauma-induced insomnia made social interactions more difficult. Other difficulties resulting from trauma included fear of commitment, increased aggression, and obsessive behaviors, all of which influenced their relationships with others.

The analysis indicated that trauma negatively impacts family relationships. Over 50% of refugees and asylum seekers reported avoiding social contact due to unfulfilled family expectations after experiencing trauma. Participants identifying as LGBTQIA+ distanced themselves from family members, viewing their family as part of the oppressive system. Some respondents hesitated to share their experiences, both to protect loved ones from hearing about their torture and out of fear of criticism. In some cases, family members blamed participants for their detention, contributing to a fractured relationship. Traumatic events also predicted more worries for family members in their home country or in detention, and others felt family life was impossible to achieve.

Nevertheless, some positive outcomes of trauma exposure were also reported, including greater family unity, stronger emotional bonds, and improved interpersonal understanding. Survivors of genocide found that trauma increased their compassion and a greater sense of interconnectedness. The positive effect of experiencing trauma extended to their family members, where they developed a new sense of appreciation. Other research found that trauma can positively impact the support received from a spouse. This positive effect extended beyond family connections, with analyses showing that group membership was 1.08 times higher for each point increase in trauma exposure.

However, three studies found no relationship between trauma and social engagement or social network size. Yet, ongoing PTSD was associated with a weak social network. Another study found that while traumatic events prior to resettlement were negatively associated with social support, adding trauma to their predictive model did not improve its explanatory power.

Employment and Education

Fifteen studies investigated how trauma affects employment or education. Although most studies pointed to the negative effects of trauma on employment, some results were mixed. In one study, over 50% of participants described avoiding stressful situations, such as searching for a job after rejection. Additionally, those experiencing PTSD often had fewer job opportunities, or trauma was linked to unemployment. Participants expressed not feeling mentally well enough to work, and others felt they had lost hope, believing trauma had led to a negative worldview where employment seemed impossible.

When employed, individuals with PTSD experienced difficulties with task-oriented performance (e.g., problem-solving, coping with stress, learning). Over time, traumatic experiences negatively predicted employment status, labor income, participation in the labor force, permanent job status, skilled occupation, hours worked per week, and work in agriculture. Traumatic events also predicted economic post-migration living difficulties, which were then linked to increased symptoms of depression. Additional results supported these findings of negative impacts.

Trauma following torture led to difficulties committing to work. For others, it motivated them to engage in activism for their home country, shifting priorities away from employment in the host country. However, in some cases, post-traumatic growth is possible, directly impacting adaptive performance: handling stress and emergencies, creative problem-solving, interpersonal adaptability, coping with unpredictable work environments, and learning new tasks. For instance, Cambodian leaders displaced in the USA used their trauma as a strength. Participants felt that trauma shifted their priorities and goals, inspiring a new dedication to higher education or career advancement. Being in the USA provided additional opportunities, fostering a belief that nothing is impossible and giving participants a renewed sense of purpose. Some embraced new missions, pursuing meaning through political activism, community engagement, or helping others. In survivors of trafficking, trauma resulted in a drive to create a better future, focusing on education and careers that help others. Despite this, five studies found that traumatic events had no effect on employment or education.

Stratification by Traumatic Events

Eleven papers focused on specific traumatic events, which can be grouped into interpersonal and war-based trauma.

Interpersonal Trauma

Eight studies explored how interpersonal trauma affects social functioning, with many specifically focusing on its link with social relationships. Survivors of abuse, trafficking, or torture experienced greater integration issues and impaired participation. Participation challenges were specifically related to a lack of engagement in community activities. Integration was further limited, as measured by a section of the PMLD checklist covering difficulties with communication, social participation, access to services, everyday living, and discrimination. Trauma led to isolation, loneliness, and struggles with trust, shame, aggression, and strained relationships. LGBTQIA+ individuals viewed family as part of an oppressive system, affecting their relationships, though some trauma survivors reported stronger family bonds and greater emotional understanding. Interpersonal trauma also affected other areas of social functioning. Symptoms of collective trauma were linked to post-migration difficulties, and family separation was associated with increased social, economic, and future-related challenges. However, growth was evident in some, with a desire for educational and employment opportunities. Cambodian genocide survivors, for example, reshaped their life goals towards education, careers, or activism, finding renewed purpose in the USA. Being close to death or experiencing a lack of basic needs was not related to participation.

War-Based Trauma

Three papers focused on trauma related to conflict. One study found that a model including gender, age, and education predicted 7% of the variation in psychosocial dysfunction. However, when war- or conflict-related PTSD was added, the model's predictive value increased to 48%. Higher levels of PTSD following war were also associated with greater self-reported integration difficulties, yet the experience of war-related trauma and probable PTSD symptoms did not predict seeking help.

Discussion

Five key themes related to social functioning among displaced populations affected by trauma were identified: post-migration living difficulties, everyday functioning, acculturation and integration, social relationships, and employment and education. While existing literature offers a detailed understanding of these themes, the review highlights that trauma mostly negatively impacts social functioning. However, positive outcomes related to social functioning after trauma are possible.

Social Functioning Factors Affected by Trauma

The studies consistently showed a strong connection between trauma and post-migration living difficulties. Most studies used the PMLD questionnaire, which includes factors like communication barriers, discrimination, family separation, employment challenges, access to support, financial stress, and social connection. Such difficulties are common, with displaced individuals often facing many challenges during the post-migration period. Recent recommendations suggest that healthcare providers and policymakers should offer comprehensive, integrated support. This should include practical help with housing, employment, the asylum process, and skills-based training. Given that trauma can worsen these difficulties, clinicians should also consider broader factors when supporting trauma recovery. Services must also ensure that displaced individuals, especially those with a history of trauma, are not further disadvantaged and that barriers (e.g., language) to access are reduced.

The effects of trauma on everyday psychosocial functioning, cultural adaptation, and integration were mixed, with reports ranging from varying effects to no effects. Regarding everyday functioning, these findings both align with and contradict the broader literature on PTSD in the general population, which consistently reports significant impairments in daily functioning with large impacts.

In terms of acculturation, the broader literature suggests that psychological acculturation (e.g., identifying with the host culture) is complex and influenced by social support, education, school-based factors in host countries, and academic achievement. The mixed findings therefore highlight the complexity of some social functioning factors. These conflicting findings may also be explained by the use of convenience samples in most of the reviewed studies, which are effective at reaching hard-to-reach populations but may consist of participants who function better in everyday life. Future research is needed to further examine the effects of trauma on everyday functioning in displaced groups.

Social relationships were mostly negatively affected by trauma, particularly through social withdrawal, perceived stigma, mistrust, and isolation. These findings are consistent with broader literature exploring social connection within displaced populations. For example, a systematic review found that rates of loneliness (15.9–47.7%) and social isolation (9.8–61.2%) in refugee populations are higher than in the general population. Trauma’s role in disconnection extends beyond refugee contexts, as childhood trauma has been linked to social exclusion in adulthood, and PTSD symptoms have a two-way relationship with loneliness.

Trust was another factor disrupted by trauma, leading to subsequent relationship issues. This theme is prominent in the literature, where refugees face distinct trust challenges, and those who have experienced interpersonal trauma show a reduced ability to trust others, with a need to rebuild trust after resettlement. Therefore, strategies that promote trust could play a crucial role in breaking the cycle of trauma and social disconnection. This aligns with the socio-interpersonal view of PTSD. This framework suggests that trauma affects three layers: (a) social emotions (e.g., guilt, shame, social withdrawal), (b) social connection (e.g., social support), and (c) culture and society (e.g., cultural values). Impacts on these areas can worsen PTSD severity, consistent with a previous meta-analysis that found social support is negatively related to PTSD severity. Drawing on existing theories, prior research, and these findings, clinicians and intervention programs should prioritize social factors and actively help rebuild social connections.

Notably, some participants showed a newfound appreciation for their family and increased compassion and interconnectedness after trauma. This may represent a growing phenomenon in the literature known as "post-traumatic growth," which suggests the potential for growth after hardship and that some individuals find benefits in stressful events. Post-traumatic growth has also been reported in displaced populations during resettlement, with factors such as high educational attainment and religious commitment associated with more post-traumatic growth. Sultani and Heinsch also reported increased post-traumatic growth in those driven to help and serve the community, which could explain why Cambodian leaders showed a positive response to trauma.

Growth was also present within the context of employment. For some displaced people, trauma sparked positive shifts in goals and values, fostering a renewed sense of purpose. This highlights the importance of post-traumatic growth and the need to promote hope, resilience, and empowerment during recovery and when seeking sanctuary. Therefore, clinicians need to support resilience building, as suggested by the socio-interpersonal framework, focusing on both trauma and broader social factors in interventions. Future research should explore how interventions can be customized to enhance post-traumatic growth, particularly in displaced populations.

Trauma Stratification

Two trauma-focused themes were identified: interpersonal trauma and war-related trauma. While these events may not always be separate, the results suggested different outcomes for those primarily affected by war versus those affected by torture. War-based trauma mainly affected psychosocial functioning and integration, while interpersonal trauma was more disruptive to social relationships. Both themes shared a common impact on social factors, but the influence was noticeably stronger in individuals who experienced interpersonal trauma.

Additional research has found that social cooperation and trust are reduced in individuals who have experienced interpersonal trauma. Therefore, interpersonal trauma may disrupt attachment systems and have a deeper impact on an individual's ability to engage in and maintain positive social interactions. This could be because experiences of torture, trafficking, abuse, or ostracism often involve betrayal, which fundamentally undermines trust and can result in avoidant attachment styles. Models of PTSD in displaced populations suggest that such changes to attachment can prolong PTSD symptoms. This emphasizes the importance of addressing social factors in clinical interventions and policy planning. On the other hand, war-related trauma, while also affecting social factors, tends to show up more in broader societal concerns, as supported by studies on veterans. This highlights the importance of considering the type of trauma when providing interventions and support plans to displaced groups.

Critical Appraisal

A key strength of this review is that it is the first to systematically combine existing research on trauma and its impact on social functioning in displaced groups who have resettled. By gathering evidence from various studies, it provides a comprehensive framework for understanding how trauma and social functioning are connected. Furthermore, by combining insights from a diverse range of studies, including cross-sectional, longitudinal, mixed-methods, and qualitative research, this review paints a detailed picture of how trauma can affect social functioning in displaced groups. This included grey literature and one report, aiming to provide a broader representation of the literature and reduce reliance on Western or Global North sources. However, the exclusion of dissertations or non-English papers may have limited how representative the sample was.

Some additional methodological limitations are noted. First, only one author screened the titles and abstracts. Given that the full-text screening showed only moderate agreement between two authors, the scope of the initial screening stage may have been limited. Among the included studies, several relied on snowball or convenience sampling. While some authors stated these samples were representative of the target population, such approaches may miss individuals most severely affected by trauma and those who experience more profound functional impairment. These populations are often difficult to engage, even under ideal conditions, and their exclusion likely limits the scope and generalizability of the findings. Consequently, this sampling bias may partly explain instances where the relationship between trauma and social functioning was inconsistent.

The review also did not explore the differences between complex PTSD and PTSD, which may have different social functioning outcomes, especially since complex PTSD often develops after interpersonal trauma. For example, non-displaced individuals with complex PTSD show significant difficulties with interpersonal relationships compared to those with standard PTSD. Therefore, future research should consider focusing on complex PTSD or distinguishing between the two conditions, as this may reveal important differences in social outcomes and inform more targeted interventions.

Another limitation is that only eight longitudinal studies were included. While these studies provide valuable insights into cause-and-effect and the long-term impacts of trauma, more longitudinal research is needed to capture how post-migration living difficulties evolve over time. Most studies also relied on semi-structured interviews or questionnaires. Future research could explore alternative designs, such as experimental or creative visual methods, to examine aspects of social functioning affected by trauma that may be overlooked in standard surveys. Despite these limitations, this review highlights several critical implications. It emphasizes the urgent need for trauma-informed interventions tailored to address the complex challenges faced by displaced populations, while also stressing the importance of societal efforts to promote integration, reduce systemic barriers, and foster post-traumatic growth in displaced groups.

Implications and Future Directions

In summary, while trauma often leads to challenges in social functioning, the literature also points to instances of resilience and post-traumatic growth. However, more research is needed to better understand the effects of specific trauma types and to adopt alternative research methods, such as visual creative approaches, which may better capture lived experiences. Furthermore, cultural, social (e.g., refugee status), and personal factors (e.g., age, gender) require deeper exploration to understand how they interact with trauma in shaping social functioning and overall well-being in displaced populations. These interconnected influences are crucial for developing interventions that consider specific contexts.

Nevertheless, the findings suggest that the effects of trauma are not uniform, and interventions should be tailored to individual experiences while also promoting post-traumatic growth. Policymakers should recognize the importance of social systems, which has been widely supported across the literature and from various perspectives. Clinicians should also consider broader social factors when supporting individuals affected by trauma. Overall, the review calls for more holistic support for refugees and asylum seekers experiencing trauma. By doing so, interventions can promote growth and improve social functioning at an individual level, and more broadly, enhance integration and cohesion in society.

Summary

By the end of 2023, 117.3 million people around the world had to leave their homes. This number includes 68.3 million people who moved to a different place within their own country, 43.5 million who sought safety in another country (refugees), and 6.9 million who asked for protection in another country but were still waiting for an answer (asylum seekers). Some experts think this number could grow to 1.2 billion people by 2050, partly because of climate change.

A refugee is someone who fled their home country and cannot go back because it is too dangerous. An asylum seeker is someone who left their country and asked another country for help and safety, but the decision has not been made yet. People are forced to leave their homes for many reasons, such as fighting, violence, unfair treatment, their personal background, or being forced into the army. While some people can find official ways to get help, many have to leave their countries through unofficial paths.

People who have been forced to move often experience very hard times, called trauma. This trauma can happen: (a) before they leave their home, (b) while they are traveling to a safe place, and (c) when they are settling into a new country. Each step has its own difficulties and can cause more trauma. During these times, people might experience war, violence, not having basic needs like food or shelter, being separated from family, and living in poor conditions.

These hard experiences often lead to many mental health problems, especially a type of stress called PTSD (Post-Traumatic Stress Disorder) in 31.5% to 43% of people. For everyone, trauma can make life much harder. It can change how people act and feel, and it can affect their body and mind.

For people who have been forced to move, trauma causes similar problems. They may have more PTSD, feel sad (depression), feel worried (anxiety), and find it harder to fit into their new communities. Some studies also show that trauma can make it hard to remember things or to think clearly. It can also raise the chance of developing other mental health conditions.

Social Functioning

Trauma and PTSD can also make it harder for people to get along in society. Social functioning means how people interact with others and how they handle their daily lives.

More simply, social functioning is about how people take part in the world around them, like working, doing social activities, and being in relationships with family and friends. This ability is very important for displaced people to successfully settle into a new country. When people settle in better, they tend to do well and help make society stronger. Ways to help displaced people settle in include better housing, jobs, language help, schooling, ways to be part of the community, avoiding being held in detention centers, and actively helping with health problems.

However, trauma makes it very hard for a person to live well in a new place. Since so many displaced people have experienced trauma, it is important to understand how they settle in and get along with others after trauma. While there has been research on how trauma or PTSD affects social functioning, the results are mixed. Some studies show that trauma really hurts how displaced people function, but others suggest that things can get better after trauma. Many studies have looked at different parts of social functioning, but no one has yet put all the information together to show how trauma or PTSD affects different areas of social functioning after people have moved.

Study Goals

Because past research has shown different results, a clear way is needed to understand how trauma, PTSD, and social functioning are connected for refugees and asylum seekers after they move. The goal was to look at all the research to see how trauma and PTSD affect how adult displaced people get along in society. Specifically, researchers wanted to find out which parts of social functioning are most affected by trauma and how different types of traumatic events change these important areas.

Method

Researchers followed certain rules for this study and wrote down their plan before they started.

Search

The plan for finding studies was made by first looking at what research was already out there. Important words were used to help find the right studies. Then, between November 2024 and February 2025, searches were done in several large online databases. They also looked for information from government websites, the United Nations, the World Health Organization, and other groups that help people. Only reports from trusted groups or studies that had been reviewed by other experts were included.

What Studies Were Included

Researchers included studies that looked at how trauma, traumatic events, or PTSD affected how adult refugees and asylum seekers (age 18 and older) got along in society. They looked at both refugees and asylum seekers to understand trauma and social functioning when people move to a new country. Studies were not included if the people lived in refugee camps, because this study focused on people who had settled in. People under 18 were not included because young people often get different help and might have a different experience when settling in. For example, some think children and young people can adjust better, and schools can help them settle. If it was not clear whether a study was about how trauma affected social functioning (and not the other way around), the full study was read carefully. Studies were included if they used tools to measure trauma that happened before moving. However, if a tool measured PTSD, it was checked to see if PTSD was causing problems with social functioning, rather than social problems causing PTSD.

Because PTSD and social functioning can affect each other, researchers only included studies where PTSD symptoms were shown to lead to social functioning problems. They did not include studies that mainly looked at how social functioning problems led to PTSD. Also, studies not written in English or those that were not main research papers (like school projects, case studies, or reviews of other papers) were not included. Within the search for general information, only reports from trusted organizations or research papers that were reviewed by experts were included. School projects were not included because it is not always clear how well each part has been checked. Finally, studies published more than 30 years ago were not included. This was done because the world has changed a lot with technology, and this can affect how people settle in and get along in today's society.

Checking Studies, Taking Out Information, and Looking at It

The process of checking studies had two steps. First, one author looked at the titles and summaries of all the studies. Then, two authors independently read the full studies. If they disagreed about a study, a third author helped them decide. All the studies that met the rules were included. The same process was used for general information found outside of research papers. After that, information was pulled out from each study, such as how it was set up, how many people were in it, what tools were used to measure trauma or social functioning, what kind of trauma was studied, what social functioning factors were looked at, and the results. If information was missing or did not make sense, the authors of those studies were contacted. One author did this part, and another author checked the information. The information was then put into a computer program to find main ideas. To look closer at different types of trauma, studies that focused on specific traumatic events were found and analyzed to see how they affected different parts of social functioning.

Checking for Fairness

Researchers checked how fair and good each study was. Two authors rated each study, and if they disagreed, another team member helped. They did not give a single score for fairness but described the quality of the studies. For general information that did not fit the main rating tool, a different tool was used to check for fairness.

Results

After removing duplicates, 1388 studies were found. After checking titles and summaries, 70 full studies were looked at more closely. Out of these, 33 studies met the rules. Five more studies were found from references and general information, bringing the total to 38 studies.

Study Details

The studies included were published between 1998 and 2024 and used different study methods: one study used mixed methods, 21 were cross-sectional (looking at one point in time), eight were longitudinal (looking over time), one used data from a trial, one used old data, and six were qualitative (looking at experiences and meanings). The research took place in many countries. In total, 15,394 people took part in the studies, coming from many different backgrounds. The people were from different countries and ethnic groups. Reasons for leaving home and specific traumatic events included: war or fighting, being treated badly for being LGBTQIA+, violence and abuse, not having basic needs, being close to death, personal trauma, family trauma, group trauma, being trafficked or tortured, being separated from family, genocide, and other traumatic events in general.

Risk of Bias

Researchers carefully checked all the papers for any issues that could make the results unfair. They used a tool for 37 papers and another tool for one paper that was not reviewed by other experts. The issues found mean that the results should be looked at carefully. Many studies clearly said who they included or left out, but ten papers were not clear about this. Thirty-three papers said their findings might not apply to everyone. This was often because they used easy-to-find groups of people or focused on specific groups, such as people from a certain country, those with a good education, people good with technology, or married people. One research team used a certain method but knew their study was not big enough to get strong results. Two other papers did not say if their measuring tools were good. Also, five papers had missing results, or it was hard to tell if all the results were there, though all papers did try to control for other factors. One descriptive paper might have been unfair because many people did not respond.

All the studies that looked at people's experiences had very few issues. The one study that used mixed methods did not fully meet all the rules. It did not clearly explain why it used both types of methods and did not put the different results together well. Lastly, the one general information paper that was reviewed met all the fairness rules.

Main Ideas

Five main ideas about how trauma affects social functioning came out of the research: problems with daily life after moving, everyday tasks, settling into a new culture, social relationships, and jobs and schooling.

Problems with Daily Life After Moving

Eight studies looked at how trauma affects problems people have after moving, such as learning a new language, feeling lonely, facing discrimination, and getting help. The research consistently showed that PTSD and traumatic experiences were linked to more of these problems.

Specifically, trauma strongly predicted worries about the future, like not knowing if they could stay in the country or fearing they might have to return to danger. One study also showed that people with serious problems after moving had experienced more traumatic events than those with fewer problems. Only one study did not find a link between the total number of traumatic events and the total number of problems after moving.

Everyday Tasks

Five studies explored how trauma affects everyday tasks, but the results were mixed. One study found a strong link between PTSD and problems with mental and social functioning. Stories from people showed that these problems were due to feeling ashamed, which led to not taking care of themselves, physical health issues after trauma, and a growing negative view of themselves. Other studies did not find a link between traumatic experiences and daily tasks or between trauma and seeking help.

Settling into a New Culture

The evidence about how trauma affects settling into a new country was mixed. Nine studies showed negative effects on settling in. More severe trauma was linked to more difficulties in fitting into the new culture. Trauma was also connected to less ability to adapt to the new culture and society, less interest in both their old and new cultures, and less skill in understanding the new culture. This connection can be made worse by trying to cope by focusing on feelings, having bad experiences with people from the new country, and stress from adjusting to a new culture. People with PTSD symptoms showed similar patterns, with less social integration and trouble learning the language if they had complex PTSD.

However, recent studies showed a more detailed picture of the link between trauma and settling in. One study found that traumatic events made it harder to keep their old culture but easier to adopt the new culture, even though earlier checks had not shown a link with adopting the new culture. Trauma had only small effects on taking part in society, except when people had experienced violence and abuse, which made it much harder to take part.

On the other hand, eight studies reported little to no effect of trauma on settling into a new culture. Traumatic events were not linked to adjusting to a new culture, fitting into Norwegian culture, or how much they focused on their old or new culture. They also did not predict cultural identity or how well they spoke English. While one study reported an effect of traumatic events on thinking and cultural integration, this effect was not strong. When it came to being involved in the community, PTSD symptoms at one point did not predict involvement later. Also, there were no differences in things like money, unfair treatment, family worries, or housing problems between people with complex PTSD and those with standard PTSD.

Social Relationships

Eighteen studies showed mixed results about how trauma affects social relationships, but most studies reported that trauma had a bad effect on good social relationships. In one study, over 70% of people with PTSD said they pulled away from others and did less. Also, in one analysis, people who felt disconnected from others had experienced more different kinds of trauma compared to other groups. Trauma was linked to weaker social groups and led to fewer contacts with the new society, because it affected mental health.

Trauma also led to more difficulties after moving related to feeling alone and lonely, which then led to feeling sad (depression), having PTSD, and having disabilities. More trauma-related thoughts were linked to less social connection, even though people who had more trauma still wanted social contact. People from Eritrea also said that trauma hurt their relationships with both other Eritreans and people from Israel.

Feeling mistrust, which led to being alone and having difficult relationships, was highlighted in studies where people shared their experiences. Specifically, survivors of trafficking said that their attackers were often friends, which made it even harder to trust others. Some felt ashamed about their traumatic experiences, which made them more isolated. Also, it was hard for them to share their experiences because others did not understand or care. Injuries from torture caused shame in social situations, and not being able to sleep because of trauma made social interactions harder. Other difficulties from trauma included being afraid to commit, becoming more aggressive, and having obsessive behaviors—all of which affected their relationships with others.

The study showed that trauma has a bad effect on family relationships. More than half of refugees and asylum seekers said they avoided social contact because they could not meet family expectations after trauma. People who identified as LGBTQIA+ kept their distance from family members, seeing their family as part of the unfair system. Some people did not want to share their experiences, both to protect their loved ones from hearing about their torture and because they feared being judged. In some cases, family members blamed people for being held captive, which hurt relationships. Traumatic events also led to more worries for family members in their home country or in detention, and others felt that a normal family life was not possible.

However, some good things also came out of trauma, such as families becoming closer, stronger emotional ties, and better understanding between people. Those who survived genocide found that the trauma made them more caring and feel more connected to others. The good effect of trauma also reached their family members, who had a new appreciation for things. Other research found that trauma can have a good effect on the support people received from their partners. This good effect went beyond family, with studies showing that group membership was more likely for each increase in trauma.

But, three studies found no link between trauma and being involved socially or the size of someone's social group. However, ongoing PTSD was linked to a weak social group. Another study found that while traumatic events before moving were linked to less social support, adding trauma to their prediction model did not make it better at explaining things.

Jobs and Schooling

Fifteen studies looked at how trauma affects getting a job or going to school. Most studies showed that trauma had a bad effect on jobs, but some results were mixed. In one study, more than half of the people said they avoided stressful situations like looking for a job after being rejected. Also, those with PTSD often had fewer job chances, or trauma was linked to not having a job. People said they did not feel well enough mentally to work, and others felt they had lost hope, and trauma had made them see the world negatively, making a job seem impossible.

When people did work, their ability to do tasks was affected if they had PTSD (like solving problems, dealing with stress, and learning). Over time, traumatic experiences predicted not having a job, lower pay, not being in the workforce, not having a permanent job, not having a skilled job, fewer hours worked per week, and not working in farming. Traumatic events also predicted financial problems after moving, which then led to more feelings of sadness. Other results also showed negative impacts.

Trauma after torture made it hard to stick with a job. For others, it made them want to work to help their home country, changing their focus away from jobs in the new country. However, in some cases, people can grow stronger after trauma. This can directly help with performance, like handling stress and emergencies, solving problems creatively, getting along with others, dealing with unexpected work, and learning new tasks. For example, Cambodian leaders who moved to the USA used their trauma as a strength. People felt that trauma changed their goals and priorities, inspiring them to focus on higher education or better careers. Being in the USA offered more chances, making them believe that anything is possible and giving them a new sense of purpose. Some took on new missions, finding meaning in political activism, helping the community, or helping others. For survivors of trafficking, trauma led to a drive to create a better future, focusing on education and jobs that help other people. Despite this, five studies found that traumatic events had no effect on jobs or schooling.

Looking at Specific Types of Trauma

Eleven papers focused on certain traumatic events, which can be put into two groups: trauma from other people and trauma from war.

Trauma from Other People

Eight studies looked at how trauma from other people affects social functioning, with many focusing specifically on its link to social relationships. Survivors of abuse, trafficking, or torture had more trouble settling in and taking part in activities. Problems with taking part were specifically about not joining community activities. Settling in was also harder, as measured by a checklist of problems after moving, including issues with talking, being social, getting services, daily living, and unfair treatment. Trauma led to being alone, feeling lonely, and struggles with trust, shame, aggression, and difficult relationships. LGBTQIA+ people saw their family as part of an unfair system, which affected their relationships, though some trauma survivors reported stronger family bonds and better emotional understanding. Trauma from other people also affected other parts of social functioning. Symptoms of group trauma were linked to problems after moving, and being separated from family was linked to more social, money, and future challenges. However, some people showed growth, wanting more education and job chances. For example, Cambodian genocide survivors changed their life goals towards education, careers, or activism, finding new meaning in the USA. Being close to death or not having basic needs was not linked to taking part in activities.

War-Based Trauma

Three papers focused on trauma from war. One study found that factors like gender, age, and education could predict 7% of problems with mental and social functioning. However, when PTSD from war or conflict was added, the ability to predict problems went up to 48%. Higher levels of PTSD after war were also linked to more self-reported difficulties in settling in, but experiencing war-related trauma and likely PTSD symptoms did not predict seeking help.

Discussion

Researchers found five main ideas about social functioning in displaced people affected by trauma: difficulties in daily life after moving, everyday activities, settling into a new culture, social relationships, and jobs and schooling. While existing research helps us understand these ideas, this review shows that trauma mostly has a bad effect on social functioning. However, good things can also happen for social functioning after trauma.

Social Functioning Factors Affected by Trauma

The studies reviewed consistently showed a strong link between trauma and difficulties in daily life after moving. Most studies used a questionnaire that covers things like language problems, unfair treatment, family separation, job challenges, getting help, money problems, and social connection. These kinds of difficulties are well known, and displaced people often face many challenges after moving. Recent advice suggests that doctors and policy makers should offer many kinds of integrated support. This should include practical help with housing, jobs, the process of seeking asylum, and training for skills. Since trauma can make these difficulties even worse, doctors should also think about other factors when helping people recover from trauma. Services must also make sure that displaced people, especially those with past trauma, are not treated unfairly and that things that make it hard to get help (like language barriers) are removed.

The effects of trauma on everyday mental and social functioning, and on settling into a new culture, were mixed, with some studies showing different effects and others showing no effects. When it comes to everyday functioning, these findings both match and go against other research on PTSD in the general population, which consistently shows big problems with daily functioning.

Regarding settling into a new culture, other research suggests that how people feel about and connect with the new culture is complex and affected by social support, education, school factors in the new country, and how well they do in school. The mixed findings therefore show how complex some social functioning factors are. These conflicting findings might also be explained by the fact that most of the studies reviewed used groups of people who were easy to find. While these groups are good for reaching people who are hard to find, they might include people who manage better in daily life. More research is needed to look at how trauma affects everyday functioning in displaced groups. Social relationships were mostly negatively affected by trauma, especially through people pulling away from others, feeling judged, not trusting, and feeling alone. These findings are similar to other research looking at social connection in displaced people. For example, one review found that rates of loneliness (15.9–47.7%) and social isolation (9.8–61.2%) in refugee groups are higher than in the general population. Trauma's role in disconnection is not just for refugees, as trauma in childhood has been linked to being left out socially as an adult, and PTSD symptoms have been shown to both cause and be caused by loneliness.

Trust was another important thing that was broken because of trauma, leading to later problems with relationships. This idea is common in research, where refugees face special trust problems, and those who have experienced trauma from other people find it harder to trust others—with a need to rebuild trust after settling in. Therefore, ways to build trust could be very important in breaking the cycle of trauma and social disconnection. This fits with the idea that PTSD affects social interactions. This idea suggests that trauma affects three layers: (a) social feelings (like guilt, shame, pulling away from others), (b) social connections (like social support), and (c) culture and society (like cultural values). The effects on these areas can make PTSD worse, which matches a previous study that found that social support is linked to less severe PTSD. Based on existing ideas, past research, and these findings, doctors and programs should focus on social factors and actively help people rebuild social connections.

Notably, some people showed a new appreciation for their family, and felt more caring and connected after trauma. This might be a growing idea in research called 'post-traumatic growth,' which means that good things can come after hard times, and some people find benefits in stressful events. Post-traumatic growth has also been reported in displaced people during resettlement, with factors like good education and strong religious belief being linked to more post-traumatic growth. Other research also reported increased post-traumatic growth in people who want to help and serve the community, which could explain why Cambodian leaders showed a positive response to trauma. Growth was also present when it came to jobs. For some displaced people, trauma led to positive changes in goals and values, creating a new sense of purpose. This shows how important post-traumatic growth is and the need to promote hope, strength, and empowerment during recovery and when seeking safety. So, doctors need to help build strength, as suggested by the social interaction idea, focusing on both trauma and broader social factors in help programs. More research should look at how help programs can be made to improve post-traumatic growth, especially in displaced people.

Types of Trauma

Researchers found two main types of trauma: trauma from other people and trauma from war. While these events might not be completely separate, the results suggested different outcomes for those mainly affected by war and those affected by torture. War-based trauma mostly affected mental and social functioning and how well people settled in, while trauma from other people was more harmful to social relationships. Both types of trauma affected social factors, but the impact was much stronger for people who experienced trauma from other people. Additional research has found that social cooperation and trust are less in people who have experienced trauma from other people. Therefore, trauma from other people might break down ways of connecting and have a deeper impact on people's ability to have and keep good social interactions. This might be because experiences of torture, trafficking, abuse, or being left out often involve betrayal, which deeply harms trust and can lead to avoiding close relationships. Ideas about PTSD in displaced people have suggested that such changes in connecting with others can make PTSD symptoms worse. This shows how important it is to deal with social factors in medical help and planning policies. On the other hand, war-related trauma, while also affecting social factors, tends to show up more in broader societal concerns, as seen in studies on soldiers. This highlights how important it is to think about the type of trauma when giving help and support plans to displaced groups.

Review Strengths and Weaknesses

A main strength of this review is that it is the first to systematically put together all the research on trauma and how it affects social functioning in displaced groups who have settled in. By combining information from different studies, it gives a full picture of how trauma and social functioning are connected. Also, by putting together insights from many different types of studies, including those that look at one point in time, over time, using mixed methods, and qualitative studies, this review gives a detailed understanding of how trauma can affect social functioning in displaced groups. This included general information and one report, aiming to show a broader view of the research and rely less on sources from Western countries. However, researchers know that not including school projects or papers not in English might have limited how well the sample represented everyone.

Researchers noted some other weaknesses in the method. First, only one author looked at the titles and summaries of the studies. Since the full study screening only showed moderate agreement between two authors, the first screening might have been limited. Of the studies included, several used easy-to-find groups of people. While some authors said these groups represented the target population, such ways of choosing might miss people who have experienced the worst trauma and those who might have more serious problems with functioning. Such people are often hard to involve, even in the best situations, and their exclusion likely limits what the findings can cover and how widely they can apply. Because of this selection bias, it might partly explain why the link between trauma and social functioning was sometimes unclear.

Researchers also did not look at the differences between complex PTSD and regular PTSD, which might lead to different social functioning outcomes, especially since complex PTSD often happens after trauma from other people. For example, people who have not been displaced and have complex PTSD show much greater difficulties with relationships compared to those with regular PTSD. Therefore, future research should consider focusing on complex PTSD or telling the difference between the two conditions, as this might show important differences in social outcomes and help create more specific help programs.

Another weakness is that only eight studies looked at people over time. While these studies give valuable insights into cause and effect and the long-term effects of trauma, more research over time is needed to capture how difficulties in daily life after moving change over time. Most studies also relied on interviews or questionnaires. Future research could explore other ways to study, such as experiments or creative visual methods, to look at parts of social functioning affected by trauma that might be missed in standard surveys. Despite these weaknesses, this review highlights several very important points. It shows the urgent need for help programs that understand trauma and are made to deal with the many challenges faced by displaced people. It also stresses the importance of societal efforts to help people settle in, reduce unfair barriers, and encourage growth after trauma in displaced groups.

What This Means and Future Steps

In short, while trauma often causes problems with social functioning, the research also shows times of strength and growth after trauma. However, more research is needed to better understand the effects of specific types of trauma and to use other research methods, like visual creative approaches, which might better show people's real experiences. Also, cultural, social (like refugee status), and personal factors (like age, gender) need to be looked at more deeply to understand how they work with trauma to shape social functioning and overall well-being in displaced people. These overlapping influences are very important for developing help programs that fit specific situations. Nevertheless, these findings suggest that the effects of trauma are not all the same, and help programs should be made for each person's experiences, while also helping them grow stronger after trauma. Policy makers should understand the importance of social systems, which has been strongly supported in research and from many different viewpoints. Doctors should also think about broader social factors when helping people with trauma. Overall, the review calls for more complete support for trauma in refugees and asylum seekers. By doing this, help programs can promote growth and improve social functioning for individuals, and more broadly improve how well people settle in and get along in society.