Abstract
Firearm-related violence is the leading cause of death for adolescents and can have lifelong ramifications, including to one’s mental health and well-being. Through a scoping review of existing literature published since 1980, the current study describes nuanced pathways through which exposure to firearm violence (direct or indirect) can contribute to the development and exacerbation of posttraumatic symptomatology during adolescence (ages 10–19). Furthermore, this review explores moderators and mediators of this relationship, shedding light on the interplay between individual, familial, and societal factors. Findings from the reviewed studies (N = 16) demonstrate various links between direct and indirect firearm exposure and short- and long-term posttraumatic symptomatology in adolescents and point to necessary solutions that encompass consistent firearm violence prevention and mental health support. Results can inform future research, policy development, and intervention strategies to mitigate the adverse psychological effects of firearm violence on the vulnerable adolescent population.
In 2020, firearms became the leading cause of death for children ages 1–19 (Centers for Disease Control and Prevention, 2023). Nearly 100,000 Americans experience firearm-related injuries annually, with over 17,000 of those being children 18 years or younger (Rajan et al., 2019). While firearm violence has profound and enduring impacts on adolescents and families nationwide, it is also marked by significant racial/ethnic and gender disparities in injury rates. In 2020, the firearm homicide rate for Black males aged 10–24 was more than 21 times higher than that for White males of the same age group (Kegler et al., 2022). These mortality and injury statistics fail to account for the broad spectrum of firearm violence experiences and exposures. Individuals can be exposed to both indirect and direct forms of firearm violence. Indirect forms of firearm violence can include hearing a gunshot, witnessing gunfire, and losing a family/friend to a firearm-related injury (Hsu et al., 2020; Tracy et al., 2019). Additionally, exposure to firearm violence during adolescence, a developmentally critical period, can have detrimental and long-lasting consequences on an individual’s health and well-being (Kagawa et al., 2020; Leibbrand et al., 2020; Magee et al., 2022). Studies have linked firearm violence exposure to adverse mental outcomes among adolescents—notably, trauma symptomatology, including posttraumatic stress disorder (PTSD) (Bergen-Cico et al., 2018; de Zambotti et al., 2018; Fitzpatrick & Boldizar, 1993; Fowler et al., 2017; Turner et al., 2019). PTSD can impede the typical developmental trajectory of adolescents by affecting cognitive and behavioral development, including cognitive confusion, academic difficulties, lowered IQ, learning disabilities, and poor language and communication skills (Attar et al., 1994; Fitzpatrick & Boldizar, 1993; Jenkins & Bell, 1994; Martinez & Richters, 1993). These cognitive repercussions can affect emotional, social, and academic functioning, thereby impacting future well-being and quality of life (Armsworth & Holaday, 1993). Ineffective cognitive skills may hinder successful adolescence to adulthood transitions and engagement with the world around them, which can lead to criminal justice system involvement or poorer health outcomes.
While many studies have examined the effects of violence exposure on trauma outcomes among children and adolescents, we focus on adolescents for two reasons. First, the onset, severity, and duration of posttraumatic symptomatology exhibit significant variability across children, adolescents, and adults. Second, rates of violence exposure increase from early to later adolescence. Consequently, it becomes imperative to explore the effects of posttraumatic symptomatology, specifically among adolescents exposed to firearm violence.
Given the epidemic of firearm violence, there has been increased research and policy discussions on adolescent exposure to violence in recent years. More studies published in the last decade examining the effects of firearm violence exposure on posttraumatic symptomatology sequelae necessitate an up-to-date synthesis of findings of new and old studies. While prior reviews have examined long-term mental health consequences of firearm injury in adults (Montgomerie et al., 2015) and adolescents (Ranney et al., 2019), our study builds on prior reviews to better understand the short-term (acute) and long-term (chronic) effects and mechanisms through which exposure to direct and indirect firearm violence can lead to posttraumatic symptomatology.
Current Study
The primary objective of this scoping review is to synthesize extant studies examining the short-term (acute) and long-term (chronic) relationship between direct and indirect adolescent firearm violence exposure and posttraumatic symptomatology (PTS) and elucidate the mechanism that can mitigate or exacerbate this association. A secondary objective is to identify research gaps and establish a set of future priorities. The current review is guided by the following research questions: (1) What are the short- and long-term effects of adolescent firearm violence on posttraumatic symptomatology? (2) What variables explain the mechanism between adolescent firearm violence and posttraumatic symptomatology and can mitigate or exacerbate this relationship? (3) What are gaps in the literature that point to future research priorities?
Understanding current research findings is critical to the development of effective public health interventions focused on reducing adolescent firearm violence and posttraumatic symptomatology. By identifying the landscape of the current evidence, we seek to provide a valuable resource for those intending to conduct research, support individuals with posttraumatic symptomatology, and identify gaps in the literature and recommendations for future studies.
Methods
Participants
We included articles investigating adolescents (10–24 years old) at the time they were examined for exposure to firearm violence (Arnett, 2007; Barrett, 1996). Early adolescence is defined as 10–13 years of age; middle adolescence is defined as 14–17 years of age; and older adolescence is defined as the ages of 18–24 (Arnett, 2007; Barrett, 1996). Based on the journal’s requirements, we excluded studies that did not break down the age range, sampled college students, only reported a mean age of firearm violence exposure, and were outside of the 10- to 24-year-old age range.
Concept
Firearm violence exposure
Firearm violence exposure is defined as victimization (i.e., being the recipient of intentional or unintentional infliction to self or between individuals who are not intimately related) and perpetration by a firearm. It can occur in communities or neighborhoods, schools, and residences. There is a spectrum of firearm violence experiences and exposures, including being shot or shot at, being threatened by a firearm, shooting a firearm at someone, losing a loved one to a firearm-related injury, hearing about firearm violence, and witnessing firearm violence. Although there is no systematic definition of direct and indirect firearm violence exposure, this study will operationalize direct firearm violence exposure as experiencing direct intentional or unintentional victimization by a firearm, perpetration, and being threatened by a firearm (Allwood et al., 2023; Hsu et al., 2020; Mitchell et al., 2021). We define indirect exposures to firearm violence as witnessing firearm violence, losing a loved one to firearm violence, and hearing about firearm violence in public places (Abdalla et al., 2022; Allwood et al., 2023; Gollub et al., 2019; Mitchell et al., 2021; Rajan et al., 2019; Stein et al., 2003). All articles that examined domestic violence, BB/airsoft firearms, and war-based firearm violence were excluded. For this review, we excluded domestic and war-based violence on the grounds that these types of violence involve interactions with firearms that are generally driven by inherently different motivations and involve trauma in more nuanced ways (Lynch & Jackson, 2021). Thus, these types of firearm behaviors warrant future review to examine the unique relationship between trauma and firearm violence exposure.
Posttraumatic symptomatology
Trauma disorders, broadly discussed in the literature reviewed for this scoping review, include posttraumatic stress disorder (PTSD) and acute stress disorder (ASD). Diagnostic criteria for diagnosis of Posttraumatic Stress Disorder are determined by the presence of intrusion symptoms, persistent avoidance of associated stimuli, negative cognitive changes and mood associated with the traumatic event(s), and increase in arousal and reactivity following exposure to a traumatic event (American Psychiatric Association, 2013). The duration of disturbance is more than 1 month and is marked by clinically significant impairment in the level of functioning (American Psychiatric Association, 2013). Diagnostic criteria for ASD include criteria related to negative mood, intrusion, dissociative, avoidance, and arousal symptoms 3 days to 1 month following traumatic event exposure (American Psychiatric Association, 2013). While these criteria are indicated in the DSM-5, some of the literature referenced utilizes previous iterations. We acknowledge trauma symptoms can be experienced without a clinical diagnosis of PTSD or ASD. Additionally, researchers investigating PTSD symptomatology in adolescents exposed to violence have noted that many symptoms often go misdiagnosed or untreated, particularly within racial/ethnic minority populations (Gollub et al., 2019; Pynoos & Nader, 1990; A. L. Roberts et al., 2011). For this scoping review, we referred to trauma disorders and symptoms discussed in the literature as posttraumatic symptomatology (PTS). We incorporated all articles into our review if they explicitly indicated an assessment of posttraumatic symptomatology. However, articles solely focused on the evaluation of depression and/or anxiety were excluded from analysis.
We included studies examining both the long and short-term effects of adolescent exposure to firearm incidents and PTS. Drawing upon previous literature, we defined studies that measure short-term (acute) PTS as those that measured and included symptoms within 3 months (Rahe, 1993). Additionally, we included studies that measured long-term (chronic) PTS as those that measured and included symptoms beyond 3 months of exposure to the violent incident. Similar characterizations have been used in previous studies to differentiate between acute and chronic PTS (Ursano et al., 1999), though not yet within the firearm literature and with adolescent populations. Thus, we sought to understand the potential effects of adolescent exposure to firearm incidents and PTS, and variables that may mediate and moderate this association over time.
Search Strategy
We conducted a scoping review in accordance with JBI methodology guidelines (Peters et al., 2020). We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) to ensure consistent methodological reporting of the scoping review.
In April 2022, we conducted an initial search reviewing titles and abstracts in PubMed/Ovid MEDLINE to identify articles from 1980 to 2022 on the following topics:
1) Adolescents (youth, adolescents, teens)
2) Firearm violence
3) PTSD/PTSS/Trauma
Subsequently, text from titles and abstracts of relevant articles and index terms used to describe articles were used to develop a full search strategy that was adapted for seven databases (Embase, PubMed/Ovid MEDLINE, CINAHL Complete Plus (EBSCO), PsycINFO (EBSCO), Web of Science, Criminal Justice Abstracts (EBSCO), and Scopus). In September 2023, we used the same search strategy and text to screen for more recent articles (2022–2023) that were not included in the previous screening process. We supplemented the search strategy by screening unpublished studies/gray literature (e.g., conference abstracts, dissertations) for references of further relevant publications.
The included articles were English-language articles published in peer-reviewed journals between 1980 and 2023. We included both domestic (United States) and international articles and excluded studies not published in English. All gray literature (e.g., conference abstracts, case studies, reports, dissertations, commentaries), duplicate studies, and reviews were excluded. Additionally, studies were excluded if they did not quantitatively include both firearm violence and posttraumatic symptomatology variables.
Study/Source of Evidence Selection
All identified citations were collated and uploaded into Zotero to remove duplicates. Remaining articles were uploaded to Covidence, a web-based tool designed to facilitate the review process.
Four trained reviewers independently screened each of the titles and abstracts of studies retrieved from the search strategy. Reviewers separately ascertained article eligibility by applying predetermined inclusion and exclusion criteria. In cases of uncertainty, reviewers favored discussed and reached consensus. Full-text papers of eligible studies were examined independently by two reviewers to ensure the eligibility of the studies. Any disagreements between reviewers regarding the study eligibility were resolved via discussion and consensus or with additional reviewer/s. All excluded studies were documented with the reasons for exclusion through PRISMA flowchart (Figure 1)
Flow diagram of article selection.
Data Extraction
The same two independent reviewers who conducted the study selection extracted data for each included study in a spreadsheet. Disagreements were resolved through discussion with the larger study team. The following information was extracted from the studies: author/publication year, study setting (USA or International; rural, urban, or suburban), adolescent sample population, participant characteristics (early, middle, or older adolescents; percent female; percent white; and percent non-white minority group), firearm violence measure (measure used; firearm specific; details about firearm measure), PTS measure (measure used; modality of the measure) mediators, moderators, and key findings relevant to the review question.
Results
The search strategy yielded 8,561 articles (Figure 1). After removing 3,729 duplicate articles, we screened 4,837 articles, of which 4,720 were excluded because they did not match inclusion criteria. Full-text articles (n = 117) were assessed for eligibility and excluded based on criteria including ineligible exposure (n = 32), ineligible outcome (n = 17), ineligible age range (n = 48), and inclusion of gray literature (n = 4). A final sample of 16 articles was included in the scoping review.
The following presents an overview of studies included in the scoping review. First, we summarize participant characteristics and study context (e.g., study setting, adolescent developmental period). Next, we synthesize each study’s findings on the relationship between firearm violence and posttraumatic symptomatology, their respective measurements, and mediators and moderators. Results are shown in Tables 1 and 2, respectively.
Adolescent Sample Demographics (N = 16).
Note. All studies conducted outside of the USA are indicated in gray.
Study Measure, Variables, and Outcomes (N = 16).
Note. Only one study in our sample tested a mediator or moderator in the association between firearm violence and posttraumatic symptomatology. This study is indicated in gray in the table and further described in the study findings column of Table 2.
Study Sample Characteristics
Most studies (75%; n = 12) were conducted in the US. Nearly 25% (n = 4) were conducted internationally, including Norway (n = 1), Finland (n = 2), and Kenya (n = 1). All the studies based in Norway and Finland reported on a specific incident. Among the US-based studies, a majority were urban (50%; n = 8), followed by rural (13%; n = 2), and suburban (6%; n = 1). One study took place both in urban and suburban settings (6%). Among the international-based studies, only one study by Mbwayo et al. (2020) reported being conducted in a rural, suburban setting in Kenya.
In addition to the geographic diversity of studies, participants were sampled from a variety of settings. All studies included a sample of adolescents who had experienced firearm violence, all of whom were recruited from various contexts: from schools, student assistance programs, counties, and community centers where exposure to firearm violence was evaluated (Breslau et al., 2004; Copeland et al., 2007; Flannery et al., 2001; Kelly et al., 2012; Mbwayo et al., 2020; Slovak, 2002); from emergency departments where patients were admitted for assault or emergency injuries (Carter et al., 2015; Gollub et al., 2019; Hamrin, 1998; McCart et al., 2006); from assessments conducted after firearm incidents, including shootings (Filkuková et al., 2016; Mancini et al., 2019; Murtonen et al., 2012; Suomalainen et al., 2011; Trappler & Friedman, 1996); and from adolescents involved with the justice system (Reid & Loughran, 2021).
While most studies focused directly on adolescents exposed to firearm violence, others included matched comparison groups based on demographic factors, including residence, family structure, drug use, or attendance at neighboring schools (Carter et al., 2015; Flannery et al., 2001; Suomalainen et al., 2011).
Fifty percent (n = 8) of studies included a sample of less than 50% female, including three articles that had all-male samples. Half of the studies (n = 8) included a sample of 50% or more females, including one article that had all-female samples. Among the studies, 6 (38%) reported less than 50% racial/ethnic minorities in their sample, and 6 studies (38%) included 50% or more racial/ethnic minorities in their samples. Four studies (25%) did not report or specify the percentage of racial/ethnic minorities, and one study did not include any racial or ethnic minorities in their sample. Among samples that included racial/ethnic minorities, Black/African American was the largest racial/ethnic group (63%, n = 10), followed by Asian (6.3%, n = 1).
Among the study sample, most participants included both middle and older adolescent developmental ages (38%; n = 6), followed by articles that included both early and middle adolescents (25%; n = 4) and all three developmental ages of adolescents: early, middle, and older adolescents (25%, n = 4). Two studies (13%) focused on one developmental period of adolescence; Breslau et al. (2004) and Mancini et al. (2019) examined older adolescents.
Relationship between Firearm Violence Exposure and Posttraumatic Symptomatology
Studies reported prevalence rates of posttraumatic symptomatology and diagnoses ranging between 13% and 56% among those exposed to firearm violence (Table 2) (Copeland et al., 2007; Hamrin, 1998). In nearly all articles, firearm violence elevated the risk of posttraumatic symptomatology. Slovak (2002) found that gun violence exposure was significantly associated with trauma with demographics and gun violence exposure, explaining 17% of the variance in total trauma. Firearm violence increased risk of screening for posttraumatic symptomatology among a wide range of adolescents, including justice-involved populations, patients admitted to the hospital as inpatient or outpatient for non-fatal firearm injury, exposed to a mass shooting at school or in the community, lost a loved one to firearm violence, witnessed a suicide, and experienced general lifetime of firearm-related exposures.
Both direct and indirect exposures to firearm violence were related to trauma symptoms. For example, Hamrin (1998) found that gunshot-injured patients had a 56% rate of acute stress disorder. Additionally, indirect exposures, including witnessing shooting/stabbing/beating were associated with higher PTS; the number of different indirect violence exposures was significantly associated with poor mental health outcomes (Gollub et al., 2019). Nearly all studies (n = 6) that examined sex differences reported females had a higher risk of PTS than males (Breslau et al., 2004; Flannery et al., 2001; Gollub et al., 2019; Mbwayo et al., 2020; Slovak, 2002; Suomalainen et al., 2011). PTS symptoms were more extreme among victimized females who had higher lifetime and current PTS than males (Gollub et al., 2019).
Most of the studies examining the association between firearm violence and trauma symptoms were cross-sectional (n = 13). Most longitudinal studies were prospective cohort designs with follow-up time ranging from 2 months to Breslau et al.’s (2004) 16 years. Copeland et al. (2007) pursued a 7-year follow-up period, Hamrin et al. (2004) conducted a 4-year follow-up, and Carter et al. (2015) conducted a 2-year follow-up. Most cohort studies investigated outcomes within the initial 1–2 years post-exposure. Notably, many longitudinal studies incorporated multiple follow-up periods, including assessments shortly after exposures.
Firearm Violence Measure
Half of the studies included firearm-specific measures (50%; n = 8), and the other half of the studies (50%) used violence measures, including some firearm-violence items (Table 2). Moreover, nearly an equal number of studies used only direct firearm violence (13%; n = 2) measures as compared with studies that measured only indirect firearm violence (19%; n = 3) measures. Examples of direct firearm violence items used in the studies were sustaining physical injury due to firearm-related violence and being threatened with a firearm (Hamrin, 1998; Trappler & Friedman, 1996). Indirect firearm violence items used in the studies include witnessing firearm violence or suicide (e.g., you saw other people being shot or being threatened with a firearm), being within the vicinity of where the firearm violence occurred, hearing about firearm violence, and losing someone to firearm violence (Gollub et al., 2019; Mancini et al., 2019; Murtonen et al., 2012).
Most studies (63%; n = 10) included both direct and indirect firearm violence incidents in their measures (Table 2). One study (6%) examined, which effects of an attack in Norway, could not be determined whether they were direct or indirect violence exposure. While we determined whether the firearm violence incidents in the measures were direct or indirect, most studies did not specify the category, and there was a wide range of categorization of the firearm violence exposure items. For example, Breslau et al. (2004) categorized items into directly experienced traumas (i.e., injury or shocking experience) and learning about traumatic events experienced by others. Flannery et al. (2001) categorized items into direct or personally witnessed, and McCart et al. (2006) categorized items into indirect violence (witnessing or being informed of less severe violent events), traumatic witnessing (witnessing or being victimized by severe violent events), and physical/verbal abuse (actual or threatened harm directed at respondent).
Several studies (n = 4) measured frequency of firearm violence incidents. Three studies categorized firearm violence exposures into different severity levels, with most categorizations being low, moderate, and high. Murtonen et al. (2012) categorized students into the mild exposure category if students were not present at school during the time of the school shooting and did not lose significant acquaintances; moderate exposure for students who were at the school but not directly exposed to the shooting and were evacuated from the school building; significant exposure if students had to escape the shooter or act to avoid danger to life, saw bodies or lost acquaintances, severe exposure if students were near danger or witnessed someone being threatened with a gun; and extreme exposure if students were in danger or witnessed someone being shot and killed or lost a family member.
Additionally, Breslau et al. (2004) and Copeland et al. (2007) calculated lifetime exposure to firearm violence. Two studies examined more than one aspect: Slovak (2002) examined frequency and lifetime exposure to firearm violence, and Flannery et al. (2001) examined frequency and environment or site at which firearm violence occurred (e.g., school, neighborhood, community, home).
Posttraumatic Symptomatology Measures
A wide range of validated measures was used to assess posttraumatic symptomatology. The Trauma Symptom Checklist for Children (TSC-C) (n = 4) was the most common trauma measure used across studies (Table 2). Other measures include UCLA PTSD Reaction Index (PTSD-RI) (Filkuková et al., 2016; Mbwayo et al., 2020), PTSD section of the World Health Organization Composite International Diagnostic Interview (Breslau et al., 2004), Mini-International Neuropsychiatric Interview for Children and Adolescents (MINI/MINI-KID) (Carter et al., 2015), the Child and Adolescent Psychiatric Assessment (CAPA) (Copeland et al., 2007), Emotional Wellness Screener (Gollub et al., 2019), Child PTSD Reaction Index (CPTSD-RI) (Hamrin et al., 2004), PTSD Self Report Scale (PSS-SR) (Mancini et al., 2019), Impact of Event Scale (IES) (Murtonen et al., 2012; Suomalainen et al., 2011), PTSD of Composite International Diagnostic Interview (CIDI) (Reid & Loughran, 2021), and Post-traumatic Stress Disorder Scale (Trappler & Friedman, 1996). Furthermore, most of the measures were self-reported (63%; n = 10). Other measures were clinician/health personnel administered (25%; n = 4), and research team administered (13%; n = 2).
Mediator and Moderators
Among studies that tested associations between adolescent firearm exposure and posttraumatic symptomatology, only one study tested a moderator of this relationship.
Murtonen et al. (2012) found that psychosocial support moderates the impact of trauma on students following a school shooting in Finland in 2007. Factors such as female gender, severity of trauma experienced, psychiatric disturbances, and initial levels of posttraumatic distress influenced the likelihood of receiving psychosocial support. This support is crucial to mitigating posttraumatic symptomatology, especially for adolescents with high levels of trauma-related symptoms; half of these students reported immediate support was beneficial. No studies tested mediators in the pathway between adolescent firearm exposure and PTS.
Discussion
This scoping review synthesized current literature to examine the impact and underlying mechanisms of adolescent firearm violence on posttraumatic symptomatology. We identified 16 articles from 1980 to 2023. Several important findings emerged from this investigation. First, this review pointed to a variety in demographic representation of the sample, including developmental stage, sex, and geographical representation. Overall, results demonstrate that firearm violence is a global issue, and no one demographic subgroup is exclusively impacted. Most participants included both middle and older adolescent developmental age (39%). Future studies should seek to better understand how early adolescent groups are impacted by firearm violence and posttraumatic symptomatology to develop upstream approaches for prevention. Furthermore, additional research should include all developmental ages of adolescents (early, middle, and older) and compare differential effects across contexts (elementary, middle, and high school), as the developmental stages have substantial variety in terms of exposure to firearm violence and manifestations of PTSD (Cimolai et al., 2021). We can consider the sensitive developmental points for successful intervention by comparing differential effects across developmental periods and contexts. Adolescence is a period with greater exposure to broad community violence, and rates of violent victimization increase from adolescence to early adulthood (Lambert et al., 2005), thus, understanding how and when to intervene for appropriate adolescent groups can ensure developmentally appropriate approaches for violence prevention.
This review demonstrated that both males and females are impacted by firearm violence and posttraumatic symptomatology. However, there may be variations in the prevalence and nature of firearm violence exposure between male and female adolescents, calling for additional research to better understand gender-specific risk factors that contribute to the development and persistence of PTS in the aftermath of traumatic events, including firearm violence exposure. For example, a review of data on gender differences in urban adolescents indicated that males were more likely than females to be victims of and witnesses to violent acts (Buka et al., 2001). Studies exploring sex differences in the manifestation of PTS following firearm violence exposure can shed light on potential variations in symptomatology, coping mechanisms, and help-seeking behaviors. By identifying specific vulnerabilities or protective factors associated with sex, researchers, and policymakers can design targeted interventions aimed at reducing prevalence of firearm violence and mitigating its impact on the mental health of adolescents.
This review also uncovered geographical trends in current literature, demonstrating that most studies focused on the topic were based in the USA (75%) and urban settings. Further research should examine additional contexts, including international settings, to better understand how additional geographical areas are supporting mental health of adolescents in the aftermath of traumatic events, including firearm violence exposure. Rural and suburban areas experience higher rates of firearm homicides, school shooting fatalities, and handgun carriage compared to urban areas (Livingston et al., 2019; Reeping et al., 2023; Schleimer et al., 2023). This discrepancy highlights the need for future research to focus on rural regions to understand the contextual differences. Investigating these differences is essential because elevated firearm homicide rates in rural settings may result in increased exposure to various forms of firearm violence (e.g., homicides, suicides), potentially leading to distinct PTS outcomes.
Based on this review, it is evident that this issue impacts individuals from diverse racial and ethnic backgrounds. Previous research has demonstrated that all races and ethnic groups are impacted by community violence but may manifest differently within specific contexts (Cooley-Quille et al., 2001). Economically marginalized, racially diverse urban communities, influenced by historical and ongoing systemic community disinvestment, may exhibit distinct patterns in the development and expression of PTSD symptoms following firearm violence (Ford et al., 2015; Poulson et al., 2021; Poulson et al., 2023). A comprehensive understanding of these nuances is essential for dismantling health disparities and promoting equitable mental health outcomes. Additionally, none of the studies in this review included Hispanic or Latinx populations. Given that Hispanic adolescents are disproportionately impacted by firearm homicide (Roberts et al., 2023), future research should focus on including this population to uncover and develop prevention strategies within Hispanic adolescents. Ultimately, acknowledging and researching the intersectionality of identities, including race, gender identity, and sexual orientation, with firearm violence and posttraumatic symptomatology not only contributes to a more inclusive and culturally responsive mental health approach but also aids in the development of effective policies that address diverse individual experiences.
The demographic results highlighting the prevalence of firearm violence universally underscore the urgent need for a global understanding of the intricate relationship between firearm violence and posttraumatic symptomatology. Firearm violence is not confined to specific regions or demographics; it permeates societies globally, affecting individuals across various age groups, contexts (i.e., elementary, middle, and high school), socio-economic statuses, and cultural backgrounds. The ubiquity of this issue implies that the impact of firearm violence on mental health, particularly the development of PTS, is a global concern that transcends geographic and demographic boundaries.
This review investigated the presentation and duration of posttraumatic symptomatology. Results demonstrated that adolescent firearm violence is associated with elevated short- and long-term posttraumatic symptomatology. While this finding corroborates the numerous studies that link firearm violence to posttraumatic symptomatology, our findings highlight a notable research gap in understanding the long-term consequences of posttraumatic symptomatology. The predominant study design observed in our review was cross-sectional, with most of the longitudinal cohort studies having a follow-up period of up to 1 year. Moreover, most of the cohort studies relied on hospital data, specifically examining individuals who experienced non-fatal firearm injuries and were subsequently hospitalized. This finding suggests the potential dearth of longitudinal survey data that goes beyond 1 year and assesses prolonged posttraumatic symptomatology.
Nevertheless, conducting a short-term follow-up of 1 month is crucial, given that the DSM-5 stipulates a requirement for the persistence of defined symptoms for more than 1 month for a PTSD diagnosis. Understanding both the acute and long-term consequences of PTSD is imperative to elucidate factors influencing why certain adolescents exposed to firearm violence may exhibit acute posttraumatic symptomatology without enduring long-term effects. Evidence indicates that, despite prevalence of acute stress reactions in most children, only a subset will progress to develop persistent PTSD outcomes (Cimolai et al., 2021). For instance, Cimolai et al. (2021) observed from the literature that children exposed to mass shootings manifested acute stress reactions in the short-term, yet only a minority experienced persistent PTSD. Nevertheless, adolescents may exhibit more acute and persistent PTSD outcomes than children, given that adolescents face elevated risk of encountering multiple forms of violence as they transition into adulthood; this cumulative effect can have differential effects on PTSD. Nevertheless, findings from Cimolai et al. (2021) may be limited by the lack of long-term studies that extend beyond 3 years to track individuals from adolescence to later stages of life.
Building on prior evidence linking firearm violence to posttraumatic symptomatology, more cohort studies with follow-up periods greater than one year tracking adolescents into adulthood, are essential to understanding the onset and severity of posttraumatic symptomatology over time. PTSD symptoms may manifest immediately, within weeks, months, or even years later, and can be long-lasting, with chronic PTSD enduring for many years, particularly if untreated (National Institute of Mental Health, 2024). Particularly important is the inclusion of a 6-month follow-up period or beyond in studies evaluating ASD, given that extant research indicates a prevalence of 80% of people with ASD have PTSD 6 months later (Cahill & Pontoski, 2005). Subsequent investigations should address the dynamics of ASD and PTSD over time in adolescents who have been exposed to firearm violence. Furthermore, future research is needed to explore temporal differences in specific posttraumatic symptomatology (e.g., intrusion, avoidance, change in cognitions and mood, marked alterations in arousal and reactivity) presenting in adolescents in relation to the type(s) of firearm exposure (e.g., school violence, suicide completion, community violence). This is particularly important given that adolescence is a critical developmental period that can affect adult health, with multiple exposures to violence that can compound and prolong the effects of PTS (Sisk & Gee, 2022).
Our review identified one study that examined variables that can either attenuate or exacerbate the association between adolescent firearm violence and PTS and no studies identified the mechanisms through which adolescent firearm violence can give rise to PTS. Additional research is necessitated to investigate variables situated along the pathway connecting adolescent firearm violence and specific PTS, and variables that can mitigate or exacerbate this relationship. A focused examination elucidating risk and protective factors that moderate and mitigate the impact of firearm violence on posttraumatic symptomatology, such as PTSD, may have greater clinical utility and is essential for informing interventions aimed at mitigating the psychological sequelae in adolescents.
Importantly, our review underscores limitations in operationalizing posttraumatic symptomatology and firearm violence exposure. Results from this review demonstrate little consistency in the ways researchers use, define, measure, and operationalize trauma symptoms (e.g., psychological distress, emotional distress, mental distress, post traumatic stress symptoms, posttraumatic stress disorder, traumatic stress). Some measures were based on self-report, while others were administered by clinicians/health personnel. Consistency is vital for comparing findings, synthesizing existing knowledge, advancing research, and promoting a comprehensive understanding of the psychological consequences of trauma, such as exposure to firearm violence. Without standardized operationalization, variations in assessment tools and criteria may lead to disparate research outcomes, hindering the establishment of reliable patterns and generalizable insights.
By operationalizing the ways researchers have measured firearm violence exposure (i.e., direct, indirect), we identified considerable heterogeneity across definitions employed within studies. Particularly noteworthy was the lack of consensus regarding categorizations of exposures, including witnessing firearm violence (i.e., seeing someone being injured or killed by a firearm), hearing a gunshot, being threatened with a firearm, and losing a loved one to firearm violence as either indirect or direct exposures. Gollub et al. (2019) consider indirect exposure as witnessing violence (e.g., Witnessing violence, witnessing a shooting/stabbing/beating, witnessing a murder, or experiencing the murder of someone close). However, Trappler and Friedman (1996) consider direct victimization as witnessing violence. While there was greater agreement on categorizing direct victimization (e.g., being shot at or injured by a firearm) as direct exposure, variations in definitions of direct exposures were evident.
While the majority of studies examined different effects of direct and indirect exposures to firearm violence on PTS outcomes, three studies combined exposures in their findings (Kelly et al., 2012; McCart et al., 2006; Slovak, 2002). This variation in handling exposures—either distinguishing between them or merging them—reflects the range of existing, validated firearm measures and scales. For instance, Hastings and Kelley (1997) introduced the Screen for Adolescent Violence Exposure (SAVE) to assess violence in schools, homes, and communities for Black/African American inner-city adolescents in grades 6 through 12. A confirmatory analysis revealed three distinct factors—traumatic violence, indirect violence, and physical/verbal abuse—and confirmed its validity with its strong correlation to PTS outcomes (Hastings & Kelley, 1997). Similarly, the Recent Exposure to Violence Scale by van Dulmen et al. (2008) analyzed violence exposure across ethnically diverse children and adolescents in grades 3 to 12, identifying a seven-factor structure that highlighted differences in victimization and witnessing violence across various contexts (van Dulmen et al., 2008). Furthermore, Beseler et al. (2020) developed the Firearm Risk and Safety Tool for children aged 2 to 17, identifying a single factor related to gun violence exposure strongly linked to trauma symptomatology (Beseler et al., 2020).
The heterogeneity within the dimensions of firearm violence—whether considered as a single or multidimensional construct (e.g., direct or indirect)—underscores the need for rigorous evaluations. These evaluations should be theoretically grounded and focus on validating the measures used to distinguish between firearm violence types, characteristics, and attributes. Such rigorous assessments not only deepen our understanding of the complexity, nuances, and nature of firearm violence but can also contribute to a unified definition.
Considering the nascent state of the literature on firearm violence, establishing a consensus on the definition of firearm violence exposures is critical, especially given the evolving nature of this research where potential differential effects may be present. The absence of shared terminology among researchers and clinicians, particularly concerning firearm violence/victimization, poses a challenge in addressing broader issues across diverse fields and settings. Establishing common understanding and consensus through clarifying definitions is salient to effectively address firearm violence and its mental health sequelae for adolescents. Future research should examine the ways firearm research is currently theorized and empirically measured within the current literature. Through comprehensive measures focused on firearm violence, researchers can categorize the types of violence (indirect vs. indirect) and compare the categorizations to reach a consensus.
Additionally, although validated firearm violence measures have been applied across a wide range of demographic and adolescent age ranges, our scoping review identified a significant gap in the frequency of assessing direct and indirect firearm violence exposures across different adolescent age groups (Beseler et al., 2020; Hastings & Kelley, 1997; van Dulmen et al., 2008). Notably, the studies that assessed both direct and indirect exposures in early adolescents were assessed less frequently than middle and older adolescents, with middle adolescents having the highest assessments of direct and indirect exposures, followed by older adolescents. Given the strong correlation between validated firearm violence measures and PTS outcomes (Beseler et al., 2020; Hastings & Kelley, 1997), extending this research focus to younger children and early adolescents can help mitigate the impacts of trauma at this sensitive developmental period. This is particularly important as adverse childhood experiences (ACEs), such as early firearm exposure, can have a unique impact on the development of severe posttraumatic symptoms (Goldenson et al., 2021; Rajan et al., 2019). Research from Rajan et al. (2019) advocates for the inclusion of firearm exposure in the ACE measure, which, in part, would provide increased opportunities to respond to traumatic experiences in adolescents (Rajan et al., 2019). Applying validated measures to children and early adolescents would also address the research gap concerning the lack of literature on the mental health outcomes of young children (ages 0–8) who have been exposed to firearm violence (Holloway et al., 2023). Given the prevalence of direct and indirect firearm exposure in children and adolescents in a variety of contexts (e.g., school, community, home), more research is needed to understand the implications of direct and indirect firearm violence at different developmental phases for adolescents (Bancalari et al., 2022). By clearly defining and distinguishing the effects of different modalities of firearm violence on PTS across all adolescent age groups exposed to firearm violence, efforts can be made toward keeping adolescents safe.
There are notable areas that warrant attention, particularly the measurement of lifetime firearm violence, environment (e.g., school, home, community), and proximity to firearm incidents (e.g., physical proximity to firearm incident, emotional proximity including relationship to those who were involved in the event). Existing research often focuses on assessing the immediate aftermath of firearm violence or short-term consequences, leaving a substantial gap in the long-term impact and cumulative effects over an individual’s lifetime. Measuring lifetime exposure to firearm violence is crucial for comprehensively capturing the full spectrum of trauma and its potential enduring consequences on mental health. Addressing these research gaps is crucial to advancing our understanding of the multifaceted relationship between firearm violence and mental health outcomes. It would enable researchers to develop more accurate risk assessments, intervention strategies, and preventive measures that encompass the complexities of lifetime exposure, environmental influences, and proximity to incidents of firearm violence. Overall, bridging these gaps will contribute to a more holistic and nuanced comprehension of the long-term repercussions of firearm violence on individuals and communities.
Limitations
Findings from this scoping review should be considered in the context of several limitations. First, a primary limitation of our scoping review is the exclusive focus on posttraumatic symptomatology without a separate assessment of anxiety and depression. We acknowledge that posttraumatic symptomatology, including PTSD, is often comorbid with other mental health outcomes, such as anxiety and depression. However, we wanted to specifically investigate the relationship between adolescent firearm violence and PTS, including conditions such as PTSD and acute stress disorder, recognizing that not all individuals with PTSD will necessarily develop comorbid depression and anxiety. Therefore, we deemed it important to examine the development of posttraumatic symptomatology, separate from anxiety and depression. While recognizing the importance of investigating other comorbid disorders, this scoping review serves as a foundational exploration and precursor to future systematic reviews with the hopes that future studies can delve into the examination of other comorbid issues like anxiety and depression in conjunction with PTSD among adolescents exposed to firearm violence.
Second, we included studies that measured violence more broadly if they incorporated firearm incidents in their violence measures. While this is a common limitation in the data that many researchers face, it nevertheless undermines the internal validity of the study. Further, it hampers the ability to assess disparate effects of exposure to violence on PTS. Nevertheless, we speculate that these violence measures are likely to represent an underestimate compared to the studies that focus specifically on firearms. This assertion is based on existing studies suggesting that exposure to firearms is associated with more elevated mental distress compared to victimizations involving other weapons (Kagawa et al., 2020). Further, the lethality of firearms may be more traumatizing for bystanders (Opara et al., 2020). Moreover, it is important to examine the potential disparate effects of weapons/violence on PTS. Recognizing different modes of violence may elicit distinct psychological responses; future studies should examine the differential effects of violence exposure, particularly weapons, to provide more granular insight into the specific consequences.
Conclusion
Adolescents represent a vulnerable demographic, and the impact of firearm violence on their lives can have profound and lasting consequences, evidenced by the findings from this scoping review. This work serves as a critical first step toward establishing consistent approaches for measuring and rectifying firearm violence and its impact on mental health. Although considerable efforts have been made to examine exposure to violence and PTS, no studies have synthesized the literature on the short- and long-term effects of adolescent firearm violence on posttraumatic symptomatology and point to research gaps. By actively and collectively working towards solutions that encompass consistent firearm violence prevention and mental health support, we not only safeguard the lives of adolescents but also contribute to fostering a safer and more nurturing environment for the generations to come.
Footnotes
Acknowledgements
We acknowledge Kate Saylor for the development of the search terms that helped guide this scoping review. We thank Megha Uberoi and Xiwen Tan for assisting with the article screening process. Additionally, we acknowledge Gaurab Maharjan for providing research organization to help guide this review.
Data Availability
Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by the Bureau of Justice Assistance [2019-YS-BX-K001].
