Introduction

Potentially traumatic events, including adverse childhood events (e.g., maltreatment, caregiver psychopathology, violence in the home), are common among European children and adolescents with data from multi-country surveys showing that approximately 50% of youth have experienced at least one adverse childhood event in their lifetime^1,2. Exposure to traumatic events during childhood and adolescence is associated with a myriad of mental health concerns including posttraumatic stress symptoms (PTSS) and posttraumatic stress disorder (PTSD) and substance use disorders (SUD). Moreover, there is evidence of reciprocally reinforcing influences of trauma and substance use, such that earlier and more frequent experiences in one domain predict greater risk for problems in both domains over time.

PTSD is generally characterized by persistent intrusive thoughts associated with a traumatic event, negative alterations in mood and cognitions, avoidance of reminders of the traumatic event, and hyperarousal in response to internal or external cues that trigger traumatic stress reactions^3-5. Epidemiological studies estimating population prevalence of traumatic stress disorders are rare, particularly outside of the United States. One study of Swiss adolescents found that 56% of youth experienced a potentially traumatic event with 4.2% of youth currently meeting criteria for post-traumatic stress disorder⁶. These estimates are consistent with those found in the United Kingdom⁷. However, studies likely underestimate the experiences of youth living in areas with active war or refugee youth who were displaced due to war because of the the challenges of conducting research in those settings⁸.

Estimates of substance use prevalence among European youth are more widely available. Data from the 2019 European School Survey Project on Alcohol and other Drugs showed an average of 79% of lifetime use of alcohol among 15- to 16- year-olds across 49 European countries, with 47% of youth using alcohol in the past 30-days⁹. On average 16% of youth engaged in lifetime cannabis use across 49 countries, while 5% of youth have used other illicit substances such as ecstasy, cocaine, hallucinogens, heroin, or gamma hydroxybutyrate (GHB). However, the prevalence of substance use varies across countries. Cannabis and illicit drug use among youth appear lowest among Nordic countries (e.g., Sweden and Norway) and Southeast Europe (e.g., Greece and Kosovo) with lifetime prevalence lower than 10%, and higher among Baltic Countries (e.g., Lativa, Lithuania, and Estonia) and Central European Countries (e.g., Germany, Poland, and Czechia) with lifetime prevalence higher than 20%. Similar patterns of alcohol and cannabis use have also been found in the Health Behaviour in School-aged Children (HBSC) survey¹⁰.

A SUD is characterized by continuing to use substances despite substance-related problems, broadly categorized as impaired control, social impairment, risky use, and pharmacological effects (e.g., tolerance and withdrawal)¹¹. Data from the 2021 Global Burden of Disease study estimated that 3.13% of 15- to 19-year-old European youth are living with a SUD¹². Approximately 1.59% of youth have cannabis use disorder, 1.10% of youth have alcohol use disorder, and less than 1% of youth have another illicit SUD. The prevalence of SUDs also varied across European countries with 4.5% of youth in Western Europe having a SUD, followed by 2.60% of youth in Eastern Europe, and 2.45% of youth in Central Europe.

While estimates of SUD are relatively low, trauma-related and substance-related problems commonly co-occur in youth, resulting in disproportionately high rates of SUDs among youth with PTSS or PTSD– and vice versa – relative to population prevalence. Approximately 24-30% of youth with PTSD also meet criteria for a comorbid SUD, whereas 13-25% of youth with a primary SUD have a diagnosis of PTSD.¹³ Estimates of co-occurring disorders are even higher among adults (30-50%), with up to 85% of individuals seeking treatment for PTSD having a comorbid SUD^13,14. When considering the discrepancy between the prevalences of co-occurring PTSD and SUD in youth and adults, it is important to remember that traumatic exposures are often underestimated and difficult to verify in youth. Many youth do not have insight into the relationship between traumatic exposures and trauma-related mental health problems¹³. Youth may also have significant PTSS without meeting criteria for PTSD.

Overall, trauma- and substance-related disorders are likely to be underdiagnosed in youth, perpetuating challenges accessing evidence-based care and often prolonging trauma- and substance-related problems into adulthood. Herein, we will explore the strong bidirectional relationship between trauma and substance use, review the clinical implications of comorbid trauma- and substance-related disorders, discuss evidence-based treatment of these co-occurring disorders, and propose recommendations for emergency medicine providers.

Bidirectional relationship

There is a well-established bidirectional connection between potentially traumatic events, trauma- and stressor-related disorders, and substance use^13,15-17. Traumatic events during childhood increase youths' risk for substance use problems, including higher risk of developing a SUD^18-22. The type of traumatic event and experiencing multiple traumatic events, or poly-victimization, may also contribute significantly to the increased risk of substance use problems. Of potentially traumatic events, interpersonal violence (e.g., physical or sexual assault) may lead to the highest risk of substance use problems^15,16. In fact, youth who are physically or sexually abused have a 12-fold higher odds of regularly using cannabis or alcohol by age 10 years and an eight-fold higher odds of heavy drinking by age 14 years²³. Similarly, exposure to multiple traumatic experiences is associated with a three to five times higher odds of developing a SUD compared to youth who have experienced a single traumatic event^16,24. Similarly, substance use during adolescence is associated with increased risk of experiencing a potentially traumatic event²⁵. Adolescent substance use is associated with higher levels of risky behaviors and victimization²⁶.

A diagnosis of PTSD is also associated with increased risk of substance-related problems. Adolescents with PTSD are four times more likely to have alcohol use disorder, six times more likely to have cannabis use disorder, and nine times more likely to have a SUD for other illicit drugs (e.g., cocaine, methamphetamines, opioids) than adolescents without PTSD²⁷. Among youth presenting to the emergency department, a PTSD diagnosis is associated with higher odds of being diagnosed with a SUD (aOR = 1.36, 95 %CI:[1.04, 1.79])²⁸. A diagnosis of PTSD in youth is also associated with increased risk of using multiple substances, or polysubstance use²⁹. Factors that may explain the high rates of comorbidity between trauma- and substance-related disorders have been outlined in the shared vulnerability, susceptibility, and self-medication hypotheses (Table 1), as well as in models detailing common neurobiologic etiology between the disorders.

SHARED VULNERABILITY, SUSCEPTIBILITY, AND SELF-MEDICATION HYPOTHESES

While many youths experience potentially traumatic events, the majority do not develop PTSD. Similarly, most youths who use psychoactive substances ultimately do not develop a SUD. However, the co-occurrence of trauma-related and substance-related problems sharply increases the prevalences of both PTSD and SUD. This suggests a collective vulnerability that predisposes individuals to developing these comorbid disorders³⁰. The shared vulnerability hypothesis proposes that trauma- and substance-related disorders share common risk factors^30,31. These risk factors include individual psychiatric (e.g., impulsivity) and biologic (e.g., family history of substance use and intergenerational trauma) factors, social and familial factors (e.g., inadequate parental support), and other environmental factors (e.g., availability of substances).

Overall, among those who experience traumatic events, youth with a SUD are at up to four times higher risk of developing PTSD³² and more likely to experience prolonged or exacerbated PTSS³³. First proposed by Chilcoat and Breslau³⁴, the susceptibility hypothesis posits that when individuals experience a traumatic event, those who use substances are at higher risk of developing PTSD than those who do not^13,14,34,35. Substance use disrupts the biologic stress response system, interfering with the youth's ability to effectively cope with traumatic events³². This results in increased anxiety, hyperarousal, and poor coping following a traumatic event³⁰. Further, subsequent use of substances to avoid trauma-related symptoms may prevent habituation of traumatic memories³⁶. Taken together, these findings strongly support that youth who misuse substances are more likely to develop trauma-related problems after experiencing a traumatic event.

When considering the relationship between comorbid trauma- and substance-related disorders, PTSS have been demonstrated to mediate the relationship between traumatic events and SUDs in multiple studies^27,37-39. Implicit in the name, the self-medication hypothesis postulates that some individuals with PTSS are more prone to use substances to cope with negative internal experiences³³. Substance use becomes a mechanism to avoid intrusive symptoms, alleviate hypervigilance, and seek relief from negative affective states^33,40-42. In turn, temporary relief from PTSS positively reinforces substance use⁴³, increasing the likelihood of progression to a SUD. While the self-medication hypothesis is widely accepted, relatively little rigorous research has been conducted to evaluate the longitudinal relationship between reported self-medication and trauma- and substance-related problems, especially in adolescents³³.

COMMON NEUROBIOLOGIC ETIOLOGY

Adolescence is a vital period of neurodevelopment that is uniquely vulnerable to the harms of potentially traumatic events and substance use. Experiencing a traumatic event and misusing substances both dysregulate the biologic stress response system and result in neurobiologic changes^13,44. Accumulating research shows that trauma- and substance-related neurobiologic changes affect emotional regulation, motivation, and physiologic stress response^13,44,45. Synthesis of the literature suggests changes in the mesolimbic dopamine system, noradrenergic system, hypothalamic-pituitary-adrenal (HPA) axis, amygdala, and ventromedial prefrontal cortex (PFC) moderate arousal, hypervigilance, and anxiety, traits central to PTSD and drug-seeking behaviors in SUD^13,46.

The mesolimbic dopamine system mediates reward-motivated behaviors that underly SUD, including reward learning and cognitive processes fundamental to decision making⁴⁷. Downregulation of mesolimbic dopaminergic signaling in individuals who chronically use psychoactive substances also results in transition from using for positive effects (e.g., euphoria) to using to prevent negative effects (e.g., withdrawal, anxiety, hyperarousal, and depression)¹³. Ultimately, the transition from positive effects to negative effects subsequently reinforces compulsive patterns of intoxication and withdrawal, which subsequently worsens both trauma- and substance-related problems in youth. For example, dopaminergic-related changes include aberrant learning, reward deficiency, and anhedonia, which subsequently leads to drug craving and a higher risk of relapse in response to stressors⁴⁸.

Changes in mesolimbic dopamine signaling that are common between PTSS and SUDs are in part mediated by the noradrenergic system, a constellation of several nuclei that synthesize and release the catecholamine norepinephrine⁴⁹. The locus coeruleus, which projects throughout the cerebral cortex and thalamus, regulates several cognitive functions central to stress response, including arousal, attention, emotional regulation, learning, motor control, and cardiopulmonary functions^50,51. Traumatic stress activates the locus coeruleus, which then mediates the “fight-or-flight” response via the sympathetic nervous system^13,44. Trauma-mediated changes in noradrenergic signaling may also result in dysfunctional cue reactivity that reinforces motivation to misuse substances. Further, alterations in noradrenergic signaling and sympathetic tone associated with opioid withdrawal and alcohol use also cause dysregulated response to traumatic stress¹³.

Noradrenergic signaling also results in stimulation of the HPA axis¹³. The HPA axis consists of signaling pathways that mediate physiologic response to stress⁵². Multiple substances alter HPA and noradrenergic signaling, including alcohol, cannabis, cocaine, opioids, and nicotine⁵³. Norepinephrine is a neurotransmitter that stimulates hypersecretion of corticotropin releasing hormone (CRH) in the hypothalamus¹³. CRH then stimulates the pituitary gland to secrete adrenocorticotropic hormone (ACTH), which in turn causes the adrenal gland to produce epinephrine and cortisol⁵⁴. Traumatic stress and substance use both alter HPA-mediated signaling, resulting in a negative feedback loop that leads to hypersensitivity to stress and a maladaptive stress response¹³. As with mesolimbic dopaminergic and noradrenergic pathways, hyperarousal is characteristic of trauma- or substance-mediated changes in HPA axis signaling¹³.

The mesolimbic dopamine system, noradrenergic system, and HPA axis converge within the amygdala, a part of the limbic system that is central to processing emotions such as fear and anxiety as well as motivation⁵⁵. CRH levels in the amygdala are positively correlated with hyperarousal and increased fear in response to stress⁵⁶. In addition, hyperactivity of the amygdala, which is induced by both PTSS and alcohol use⁵⁷, is one of the most consistent neuroimaging findings observed in PTSD⁵⁸. It is postulated that this hyperactivity subsequently underlies hyperarousal and fear conditioning in PTSD and drug-seeking behaviors in response to a cue or stressor in SUD¹³.

The amygdala receives inputs from multiple cortical regions, including the PFC. Hypoactivity in the ventromedial PFC, which has been reported in both PTSD and SUD, results in amygdala hyperactivity¹³. In youth, ventromedial PFC hypoactivity is also correlated with the duration of PTSD symptoms and is hypothesized to negative affective symptoms, anxiety, and regressive behavior^58,59. Among individuals with alcohol use disorder, hypoactivity of the PFC is associated with craving and binge drinking^13,57. Hypoactivity is also associated with higher rates of relapse in response to stress⁵⁷, implicating changes in the PFC in maladaptive stress response. Overall, while neuroimaging studies are limited by sample size and methodology, synthesis of the literature consistently points to amygdala hyperactivity and PFC hypoactivity, as well as PFC-amygdala connectivity, as central to maladaptive stress response in PTSD and SUD¹³.

Clinical implications

The co-occurrence of trauma- and substance-related disorders leads to several clinical challenges. As discussed above, common neurobiologic etiology and overlapping symptomatology reinforces maladaptive stress response behaviors including substance misuse, which results in poorer behavioral health outcomes. In a large sample of adolescents receiving treatment for SUD (n=20,069), greater PTSS was found to predict increased risk of return to substance use and more substance use at treatment completion was associated with greater PTSS⁶⁰. Further, past traumatic experiences are associated with poorer treatment outcomes in youth entering treatment for SUDs⁶¹. Unremitted PTSS is also associated with poorer substance use treatment outcomes compared with individuals for whom PTSS has remitted⁶². Individuals with alcohol use disorder experience a greater number of reexperiencing symptoms, which may mediate difference in treatment outcomes.⁶² Similarly, individuals with PTSD who have a comorbid SUD experience significantly poorer physical and mental health and greater disability than those without a SUD⁶³.

Of particular concern, traumatic events and trauma- and stressor-related disorders put adolescents at increased suicide risk^16,64,65. Similarly, substance use is an independent risk factor for suicidal behavior, including increased risk of suicide attempts⁶⁶. As with the risk of substance use, interpersonal violence, particularly sexual violence, is associated with markedly higher odds of experiencing suicidal ideation or attempting suicide⁶⁷. Increased risk of suicide among youth with comorbid trauma and SUDs may be mediated by substance use, or impulsivity and risk taking while intoxicated, particularly among sexual and gender minority youth⁶⁸.

Evidence-based treatment

When considering the relationship between comorbid trauma- and substance-related disorders, PTSS have been demonstrated to mediate the relationship between traumatic events and SUDs in multiple studies^27,37-39. Despite the common co-occurrence of traumatic stress and substance use, few interventions have been developed and tested for that specific comorbidity^69,70. Several effective treatments have been shown to be safe and effective in treating concerns in each clinical domain. Most evidence-based treatments for trauma-related mental health concerns and substance use in adolescents involve time-limited courses of outpatient care where families work with a behavioral health clinician to address their needs^71-73. While these treatments are unlikely to be provided in an emergency medicine setting, familiarity with these models can help guide discharge planning, referral and case management supports, and coordination with families and other healthcare providers.

PTSD TREATMENTS

With regard to PTSD, trauma-focused cognitive behavioral therapy (TF-CBT)⁷⁴ has the most robust research evidence supporting its efficacy in reducing PTSD symptoms, including among youth who are using substances. TF-CBT has been evaluated in over two dozen randomized controlled trials (RCTs), including in Europe^75,76. TF-CBT is implemented in phases. First, youth and caregivers are equipped with education about trauma and common reactions to trauma, as well as strategies for managing distress. A key feature of TF-CBT is the use of exposure to trauma-related thoughts and feelings throughout treatment to help youth and families overcome avoidance and manage other behavioral health symptoms. This gradual exposure begins early in TF-CBT and is the focus of the second phase, which includes trauma narration and processing. Finally, youth and caregivers come together in conjoint sessions to foster open communication about the trauma and related issues and to set plans for promoting safety, resilience, and healthy future development. Reviews of TF-CBT support its effectiveness in reducing PTSS, depression, grief, and other trauma-related concerns^73,75. Evidence suggests TF-CBT is also effective in treating PTSS in youth with complex clinical profiles⁷⁷, including those who report past or current substance use⁷⁸. Other empirically supported treatments that have been found effective in addressing traumatic stress symptoms include eye movement desensitization and reprocessing (EMDR), cognitive processing therapy (CPT), and prolonged exposure (PE) adapted for adolescents^79,80.

SUD TREATMENTS

There are also several established evidence-based treatments for SUDs in youth^71,72. These interventions are also typically rooted in cognitive-behavioral principles, whereby adolescents and caregivers are taught skills for identifying and managing SUD symptoms and antecedents and consequences of substance use. Some models focus largely on working with the adolescent, whereas others focus more directly on caregivers and the family system. Effective individual therapies include CBT, motivational interviewing/ motivational enhancement therapy (MI/MET), contingency management (CM), and combinations of these interventions. Adolescent-focused models typically involve guiding youth toward personalized treatment goals through manualized sessions focused on topics like emotion regulation skills, assertive communication (e.g., refusal skills), problem-solving, and cognitive processing. Family-based SUD treatments include brief strategic family therapy (BSFT), functional family therapy (FFT), multidimensional family therapy (MDFT), and multisystemic therapy (MST). These models place substantial emphasis on the roles caregivers play in shaping their children's environments, including through intentional applications of rewards and other consequences, to modulate the risk of substance use. Collectively, these treatments have been shown to reduce adolescent substance use frequency and quantity, as well as substance-related problems.

INTEGRATED TREATMENTS

Given overlap between components of PTSD and SUD treatments for adolescents (e.g., coping skills training; overcoming avoidance; caregiver involvement; etc.), there has been a long-standing call for manualized, integrated treatments designed to address comorbid PTSD and SUD in a single course of care⁸¹. Becker and colleagues (2023) recently performed a systematic review and identified 10 RCTs evaluating interventions designed to address substance use and comorbidities in an integrated fashion⁶⁹. In line with the broader literature on SUD and PTSD interventions, the identified treatments involved cognitive-behavioral principles that were typically implemented at the individual youth or family level. Nearly all identified studies were conducted in the U.S., and only two were rated as strong using Effective Public Health Practice Project (EPHPP) Quality Assessment Tool. The first study, Stepped Collaborative Care, was not found to outperform treatment as usual for PTSD or SUD⁸².

The second study with a strong EPHPP rating was an RCT evaluating Risk Reduction through Family Therapy (RRFT)⁷⁸. RRFT was also the only treatment model focused on PTSD identified in a recent systematic review of evidence-based integrated treatments for psychiatric disorders among youth who use cannabis⁷⁰. Guided by a theoretical model that emphasizes reducing risk factors and boosting protective factors across multiple levels of the adolescent's ecology, RRFT incorporates elements of CBT and family therapy for PTSD with SUD. Early studies supported the feasibility, acceptability and initial efficacy of RRFT in open and pilot randomized trials^83,84. RRFT was evaluated in a large RCT compared to TF-CBT, the "gold standard" for PTSD, in a sample of 124 adolescents⁷⁸. While both conditions resulted in improved PTSD and substance use outcomes, youth assigned to the RRFT condition showed greater reductions in number of days of substance use, PTSD avoidance symptoms, and other outcomes up to 18 months after enrollment. An additional trial of RRFT is currently underway to evaluate its effects relative to a comprehensive adolescent SUD treatment⁸⁵.

PHARMACOLOGICAL INTERVENTIONS

While psychotherapy is first-line for PTSS and PTSD in youth, pharmacologic treatments may also be utilized in conjunction with trauma-focused therapy⁸⁶. To date, clinical trials have found little evidence for medications as monotherapies for PTSS. The most prescribed medications for PTSS are selective serotonin reuptake inhibitors (SSRIs). Randomized controlled trials (RCTs) have demonstrated the safety and tolerability of sertraline and citalopram in youth with PTSS⁸⁶. By extension, other SSRIs including fluoxetine and escitalopram are also prescribed in youth with PTSS off-label. Of note, clinical trials have found limited evidence of between group differences in youth who receive an SSRI vs placebo, which may be due to both groups receiving psychotherapy, such as TF-CBT⁸⁶. Utilization of an SSRI or other antidepressant should also be considered in youth with comorbid PTSS and depression or anxiety.

Other common targets of pharmacotherapy in PTSS and PTSD are sleep/nightmares and hyperarousal. To date, antiadrenergic agents such as clonidine, a central alpha-2 adrenergic partial agonist, and prazosin, an alpha-1 adrenergic antagonist, have not been rigorously studied in youth with trauma. Antiadrenergic agents may function primarily by dampening catecholamine transmission, which lowers sympathetic nervous system tone in youth with PTSS⁴⁴. In addition, case reports and small open-label trials support the use of these medications for sleep and hyperarousal in combination with psychotherapeutic interventions⁸⁶. Propranolol, a beta-adrenergic antagonist, may also be used off-label for hyperarousal and comorbid anxiety^44,86.

As with trauma-related disorders, psychotherapy is the primary intervention for youth with SUDs and medications may be used as an adjunct to alleviate symptoms, reduce cravings, and prevent relapse⁸⁷. Pharmacotherapies may generally be considered as agonist therapy (e.g., nicotine replacement products, methadone, and buprenorphine), adjunct treatments for symptomatic relief of withdrawal or cravings (e.g., clonidine, gabapentin, and acamprosate), and other medications (e.g., disulfiram). However, in youth there is a paucity of research studying the efficacy of medications in SUDs. As a result, most medications used for SUDs in youth are off-label and may not be widely available.

Recommendations for emergency medicine providers

Too many youths with co-occurring trauma- and substance-related disorders do not receive evidence-based treatment. Often, these youths access the healthcare system through acute care settings in times of crisis. There are several ways emergency medicine providers can support the needs of adolescents with co-occurring traumatic stress and substance use.

First, it is important to recognize that trauma and substance use are often intertwined. Understanding these connections can increase sensitivity when counseling youth with trauma who present to the emergency department for substance-related problems. It also informs the broader set of clinical needs these families often face beyond the acute presenting problem. Effective care for this population often requires coordination and collaboration among multidisciplinary team members including physicians, nurses, social workers, care managers, and other allied health professionals and youth-serving systems.

Second, systematic, universal screening of adolescents for trauma exposure and substance use should be implemented in acute care settings. Note that while youth may experience acute stress in relation to the event that resulted in the emergency department visit, they may also endorse trauma-related symptoms pertaining to prior trauma and adversity. Several brief screening tools have been validated in youth and can be implemented efficiently in acute care settings. Some of these tools are also available in numerous languages, increasing their practical and clinical utility in diverse settings and populations^8,88-93. Use of universal screening procedures can help minimize bias in case identification and help ensure at-risk youth are offered appropriate services. While youth may be reluctant to disclose sensitive information in the context of an emergency department visit, implementing standardized, trauma-informed screening protocols in a private, confidential setting will improve valid responding.

Third, when adolescents screen positive for trauma and/or substance use, a more thorough evaluation of trauma- and substance-related disorders should be conducted to better understand current functioning and to guide case management and treatment needs. Such evaluations should include diagnostic assessments, as well as assessment of related psychosocial factors like protective factors that may be leveraged to promote resilience. When available, psychiatric services integrated within the emergency department (e.g., psychiatric emergency services or consult-liaison service) may be utilized for further diagnostic evaluation and disposition recommendations. In situations where it is not feasible to conduct an evaluation during the emergency department encounter, a referral to a community-based assessment provider should be included in the discharge plan.

Fourth, adolescents with co-occurring trauma- and substance-related disorders should receive referrals to effective community-based treatment services. Whenever possible, this should include integrated treatments that address comorbid disorders. In cases where such services are not locally available, referrals to evidence-based treatment for PTSS and/or SUD may be made as these treatments can still be effective among youth with complex, comorbid clinical needs. Where integrated treatments are not readily available, emergency medicine providers can center advocacy for building a network of treatment resources on the clinical needs and experiences of these youth and their families.

Fifth, providers should implement brief motivational interventions to help adolescents and families experiencing trauma-related and substance-related problems connect to appropriate follow-up services⁹⁴. When youths are given a handout with community treatment resources, treatment engagement rates are low. Although delivery of comprehensive treatments for PTSS and SUD are often beyond the scope of what can be offered in acute care settings, motivational interventions may increase post-hospital treatment engagement. Brief interventions can also help reduce substance use and future victimization^94,95. Such interventions often require 5-15 minutes and can be delivered by physicians, nurses, social workers, case managers, or other members of the healthcare team. ED teams can also offer psychoeducation and anticipatory guidance about trauma recovery and when adolescents and families should seek professional support as they recover from an injury or illness. Lastly, ED personnel should follow up with patients and their families to monitor their efforts to obtain treatment.

Conclusion:

In conclusion, healthcare professionals — especially those working in emergency departments and other acute care settings — often play a key role in identifying and responding to trauma, traumatic stress, and substance use in adolescents. These clinical concerns often co-occur, which can complicate recovery of trauma- and substance-related disorders. Understanding the epidemiology, etiology, and evidence-based intervention strategies can equip clinicians with the knowledge and tools they need to care for these youths and their families.

Summary

A significant percentage of European youth experience adverse childhood events (ACEs), increasing their risk for posttraumatic stress symptoms (PTSS), posttraumatic stress disorder (PTSD), and substance use disorders (SUDs). A bidirectional relationship exists between trauma and substance use, with trauma increasing the likelihood of substance use and vice versa. This comorbidity presents significant clinical challenges, impacting treatment outcomes and increasing suicide risk. Effective treatments for PTSD include trauma-focused cognitive behavioral therapy (TF-CBT) and other evidence-based therapies. For SUDs, evidence-based treatments utilize cognitive-behavioral principles, often employing family-based approaches. Integrated treatments addressing both PTSD and SUD are emerging, with some showing promise. Pharmacological interventions may be used adjunctively to manage specific symptoms. Emergency medicine providers play a critical role in identifying and referring adolescents with co-occurring disorders to appropriate community-based treatment services. Universal screening for trauma and substance use, followed by thorough evaluation and referral to evidence-based care, are crucial components of effective intervention.

Bidirectional Relationship

The strong bidirectional association between ACEs, trauma-related disorders, and substance use is well-established. Interpersonal violence significantly elevates the risk of substance use problems. Poly-victimization further exacerbates this risk. Conversely, adolescent substance use is associated with heightened risk-taking behaviors and victimization. A PTSD diagnosis substantially increases the likelihood of developing an SUD, and vice versa. Several hypotheses, including shared vulnerability, susceptibility, and self-medication, attempt to explain this complex interplay.

Shared Vulnerability, Susceptibility, and Self-Medication Hypotheses

The shared vulnerability hypothesis posits that both trauma- and substance-related disorders share common risk factors, such as genetic predisposition, environmental influences, and individual characteristics. The susceptibility hypothesis suggests that pre-existing substance use increases vulnerability to developing PTSD following a traumatic event. The self-medication hypothesis proposes that individuals utilize substances to cope with trauma-related symptoms, creating a reinforcing cycle.

Common Neurobiologic Etiology

Adolescence, a period of significant neurodevelopment, is highly susceptible to the detrimental effects of trauma and substance use. Both disrupt the stress response system, affecting neurobiological pathways related to reward, emotion regulation, and stress response. Alterations in the mesolimbic dopamine system, noradrenergic system, HPA axis, amygdala, and ventromedial prefrontal cortex contribute to the co-occurrence of these disorders.

Clinical Implications

Comorbidity of trauma- and substance-related disorders leads to poorer treatment outcomes, increased risk of relapse, and diminished overall well-being. Unremitted PTSS negatively impacts SUD treatment success. The co-occurrence significantly increases the risk of suicide, particularly in the context of interpersonal violence.

Evidence-Based Treatment

TF-CBT stands out as a highly effective treatment for PTSD, demonstrating efficacy even among youth with substance use. Other evidence-based PTSD treatments include EMDR, CPT, and PE. For SUDs, CBT, MI/MET, CM, and various family-based therapies have demonstrated efficacy. Integrated treatments addressing both disorders simultaneously are still under development, with RRFT showing promise.

PTSD Treatments

TF-CBT is a multi-phased approach incorporating psychoeducation, trauma narration, processing, and conjoint sessions. EMDR, CPT, and PE are also effective treatments for PTSD.

SUD Treatments

Effective individual therapies include CBT, MI/MET, and CM. Family-based therapies such as BSFT, FFT, MDFT, and MST are also effective.

Integrated Treatments

While integrated treatments addressing both PTSD and SUD simultaneously are limited, RRFT has shown effectiveness in reducing substance use and PTSD symptoms.

Pharmacological Interventions

While psychotherapy is primary, medications may be used adjunctively. SSRIs may be considered for PTSS, and antiadrenergic agents might help manage sleep disturbances and hyperarousal. For SUDs, medication options are limited in youth, primarily used off-label.

Recommendations for Emergency Medicine Providers

Emergency medicine providers can play a vital role in identifying and addressing co-occurring disorders. Universal screening for both trauma and substance use is recommended, followed by thorough evaluation and referral to appropriate services. Brief motivational interventions can also enhance treatment engagement. Advocacy for accessible integrated treatments is crucial.

Summary

Adverse childhood experiences (ACEs) are prevalent among European youth, significantly impacting mental health. A substantial percentage experience at least one ACE, correlating with increased risks of posttraumatic stress symptoms (PTSS), posttraumatic stress disorder (PTSD), and substance use disorders (SUDs). A bidirectional relationship exists between trauma and substance use, where trauma increases the risk of SUDs, and substance use heightens vulnerability to trauma. This interplay is explained by shared vulnerabilities, increased susceptibility to PTSD after trauma in substance users, and self-medication hypotheses. Neurobiological factors further complicate this relationship, impacting reward systems, stress response, and brain regions crucial for emotional regulation.

Bidirectional Relationship

A strong bidirectional link exists between ACEs, trauma-related disorders, and substance use. Childhood trauma significantly increases the risk of substance use problems and SUDs, particularly interpersonal violence. Conversely, adolescent substance use is linked to increased risky behaviors and victimization, raising the likelihood of experiencing further trauma. PTSD also substantially increases the risk of SUDs across various substances, highlighting the complex interplay between these conditions. The shared vulnerability hypothesis proposes overlapping risk factors for both disorders. The susceptibility hypothesis suggests that substance use weakens resilience to trauma, increasing PTSD risk. The self-medication hypothesis posits that individuals may use substances to cope with trauma-related symptoms.

Shared Vulnerability, Susceptibility, and Self-Medication Hypotheses

While many youth experience ACEs, only a subset develop PTSD or SUDs. The shared vulnerability hypothesis highlights common risk factors like impulsivity, family history of substance use, inadequate parental support, and substance availability. The susceptibility hypothesis suggests that pre-existing substance use impairs the stress response system, making individuals more vulnerable to developing PTSD after trauma. The self-medication hypothesis proposes that substance use offers temporary relief from PTSD symptoms, reinforcing the behavior and potentially leading to SUDs.

Common Neurobiologic Etiology

Adolescence is a crucial neurodevelopmental period highly susceptible to the negative impacts of trauma and substance use. Both disrupt the stress response system, leading to neurobiological changes affecting emotional regulation, motivation, and physiological stress response. These changes involve the mesolimbic dopamine system, noradrenergic system, HPA axis, amygdala, and ventromedial prefrontal cortex (PFC), all vital in regulating arousal, hypervigilance, and anxiety—core features of PTSD and SUDs. These neurobiological alterations contribute to maladaptive stress responses, reinforcing problematic behaviors.

Clinical Implications

The co-occurrence of trauma- and substance-related disorders presents several clinical challenges. Shared neurobiological underpinnings and overlapping symptoms exacerbate maladaptive behaviors, leading to poorer outcomes. Greater PTSS predicts higher relapse rates in SUD treatment, while past trauma correlates with poorer treatment outcomes. Comorbidity is also associated with worse physical and mental health, increased disability, and higher suicide risk. The combination of trauma and substance use significantly elevates suicidal ideation and attempts, especially in sexual and gender minority youth.

Evidence-Based Treatment

Despite the high comorbidity, few interventions specifically address both PTSD and SUDs concurrently. Trauma-focused cognitive behavioral therapy (TF-CBT) is a well-established treatment for PTSD, effective even in youth with substance use. Other evidence-based treatments for PTSD include EMDR, CPT, and PE. Evidence-based treatments for SUDs in youth include CBT, MI/MET, CM, BSFT, FFT, MDFT, and MST. A need exists for integrated treatments addressing both disorders simultaneously, although research in this area remains limited. Risk Reduction through Family Therapy (RRFT) shows promise in this area.

PTSD Treatments

TF-CBT, supported by extensive research, is an effective treatment for PTSD, even among substance-using youth. It involves education, distress management, trauma narration, and family involvement. Other therapies like EMDR, CPT, and PE (adapted for adolescents) also demonstrate efficacy.

SUD Treatments

Effective treatments for SUDs in youth include CBT, MI/MET, and CM (individual therapies), along with BSFT, FFT, MDFT, and MST (family-based therapies). These interventions focus on skills training, managing SUD symptoms, and family system dynamics.

Integrated Treatments

While many effective treatments exist for PTSD and SUDs individually, research on integrated treatments addressing both simultaneously is limited. RRFT, showing promising results in reducing substance use and PTSD symptoms, is a notable example.

Pharmacological Interventions

While psychotherapy is the primary intervention, pharmacologic treatments may be adjunctive for PTSD and SUDs. SSRIs are commonly used for PTSS but may show limited efficacy as monotherapy. Antiadrenergic agents such as clonidine and prazosin may be useful for sleep and hyperarousal, but more research is needed. Pharmacotherapies for SUDs in youth are largely off-label due to a paucity of research.

Recommendations for Emergency Medicine Providers

Emergency medicine providers play a vital role in identifying and responding to trauma and substance use in adolescents. Recognizing the interconnectedness of these issues is crucial for providing holistic care. Universal screening for trauma exposure and substance use should be implemented. A thorough evaluation including diagnostic assessments and identification of protective factors is vital. Referrals to effective community-based treatment services, ideally integrated treatments, are essential. Brief motivational interventions can improve treatment engagement and reduce future risks.

Conclusion

Healthcare professionals, particularly those in acute care settings, are essential in identifying and addressing trauma and substance use in adolescents. The co-occurrence of these issues necessitates a comprehensive understanding of their epidemiology, etiology, and effective interventions to provide optimal care.

Summary

Many European teens experience trauma and/or substance abuse. About half have had at least one adverse childhood experience. Trauma is linked to mental health issues like PTSD and substance use disorders (SUDs). There's a strong link between the two; early trauma increases substance abuse risk, and vice versa.

Trauma and Substance Use: A Two-Way Street

Trauma significantly increases the chances of substance abuse in teenagers. The more traumatic events a teen experiences, the higher the risk. Interpersonal violence, like physical or sexual abuse, is especially damaging. Conversely, teenage substance use leads to riskier behavior and increases the likelihood of traumatic experiences. A PTSD diagnosis also dramatically raises the risk of developing an SUD.

Understanding the Connection

Several theories explain this link. The shared vulnerability hypothesis suggests that both trauma and substance abuse share common risk factors, like impulsivity or family history of substance abuse. The susceptibility hypothesis proposes that substance use makes teens more vulnerable to developing PTSD after a traumatic event. Lastly, the self-medication hypothesis suggests teens might use substances to cope with the symptoms of PTSD.

The Brain's Role

Adolescence is a crucial time for brain development, making teens particularly susceptible to the effects of trauma and substance abuse. Both disrupt the brain's stress response system, impacting emotional control, motivation, and physical reactions to stress. Specific brain areas involved in reward, stress response, and emotional regulation are affected in both PTSD and SUDs. These changes contribute to substance cravings, hyperarousal, and difficulty coping with stress.

Clinical Challenges and Treatment

Co-occurring trauma and substance abuse create significant clinical challenges. Trauma negatively impacts the success of SUD treatment, and vice versa. Untreated PTSD worsens substance abuse outcomes, increasing the risk of relapse and poorer overall health and well-being. The combination also dramatically increases suicide risk.

Effective Treatments

Trauma-focused cognitive behavioral therapy (TF-CBT) is a highly effective treatment for PTSD, even in teens who also use substances. Other therapies like EMDR, CPT, and PE are also helpful. For SUDs, cognitive behavioral therapy (CBT), motivational interviewing, contingency management, and various family therapies are effective. Ideally, integrated treatments addressing both issues simultaneously are best, but more research is needed in this area. Medications can be used alongside therapy for symptoms such as sleep problems, hyperarousal, depression, anxiety, cravings or withdrawal symptoms.

Emergency Department Role

Emergency departments play a critical role in addressing these issues. Universal screening for trauma and substance abuse is crucial. If a teen screens positive, a thorough evaluation is needed. Referrals to appropriate community-based treatment, ideally integrated treatments, are essential. Motivational interventions can encourage teens and families to follow through with treatment. Emergency departments also play a key role in advocacy for creating more comprehensive networks of support services.

Summary

Many kids in Europe have gone through tough things, like abuse or violence at home. These experiences can lead to problems like PTSD (Post-Traumatic Stress Disorder) and substance use (using drugs or alcohol). These problems often happen together, making things even harder.

The Connection Between Tough Times and Substance Use

Tough experiences in childhood make it more likely kids will have problems with drugs or alcohol. The worse the experiences, the higher the risk. Kids who use substances are also more likely to have tough experiences later on, because substance use can lead to risky behavior. Having PTSD also makes substance use more likely.

Why These Problems Happen Together

Kids might use substances to try to feel better after a bad experience (self-medication). Also, both tough experiences and substance use change the brain in ways that make it harder to cope with stress.

What Happens When Kids Have Both Problems

Having both PTSD and substance use makes things much worse. It's harder to get better, and it increases the risk of suicide.

Getting Help

There are good treatments for both PTSD and substance use. Therapy, like TF-CBT (Trauma-Focused Cognitive Behavioral Therapy), helps kids cope with trauma. Other therapies help with substance use problems. Sometimes, medicine can also help.

Helping Kids in the Emergency Room

Emergency room doctors and nurses can help kids with these problems by:

• Checking for signs of trauma and substance use.

• Doing a thorough check-up and making a plan for treatment.

• Referring kids to specialists for help.

• Giving families brief advice and support to find help.

Conclusion

Helping kids who have gone through tough times and are using substances needs teamwork between doctors, therapists, and families. Early help is important for a better future.