Sleep Problems Among Black Youth Exposed to Police Violence on Digital Media.

Findings from a recent survey of a community-based sample of Black youth ages 12 through 21 in Baltimore City, Maryland (n = 345) reveal that viewing fatal police violence videos is associated with significant increases in the odds of youth sleep disturbances, and about 30% of this association is attributable to emotional distress after viewing the videos.

Firearm Violence Exposure and Functional Disability among Black Men and Women in the United States.

This study investigates the relationship between firearm violence exposure and functional health among Black adults in the United States (US). We examined associations between different forms of firearm violence exposure (direct, indirect, and community) and functional health with particular attention to differences across sex groups. We used survey data from a nationally representative sample of 3015 Black adult Americans to analyze associations between types of firearm violence exposure and four aspects of functional disability including: the ability to concentrate, walk/use stairs, dress/bathe, and run errands among males and females. The findings indicate notable disparities in exposure and health outcomes based on the exposure type and cumulative exposure to violence. Among males, functional disability was associated most closely with community violence exposure, while direct threats of firearm violence were most consequential for functional health among females. High cumulative exposure to firearm violence was linked to significant risks to functional health, particularly among females. The results shed light on sex differences in the repercussions of firearm violence exposure and emphasize its implications for daily functioning and health. This study contributes to the understanding of the multifaceted impacts of firearm violence on functional well-being and highlights the need for inclusive and culturally sensitive healing approaches based in community settings. There is a critical need for heightened awareness and strategies to enhance the well-being of those disproportionately affected by firearm violence in the US.

Neighborhood Racial Composition and Unequal Exposure to Violent Crime in Everyday Contexts.

Exposure to violence is a critical aspect of contemporary racial inequality in the United States. While extensive research has examined variations in violent crime rates across neighborhoods, less attention has been given to understanding individuals' everyday exposure to violent crimes. This study investigates patterns of exposure to violent crimes among neighborhood residents using cell phone mobility data and violent crime reports from Chicago. The analysis reveals a positive association between the proportion of Black residents in a neighborhood and the level of exposure to violent crimes experienced by residents. Controlling for a neighborhood's level of residential disadvantage and other neighborhood characteristics did not substantially diminish the relationship between racial composition and exposure to violent crimes in everyday life. Even after controlling for violence within residents' neighborhoods, individuals residing in Black neighborhoods continue to experience significantly higher levels of violence in their day-to-day contexts compared to those living in White neighborhoods. This suggests that racial segregation in everyday exposures, rather than residential segregation, plays a central role in racial inequality in exposure to violence. Additionally, the analysis suggests that neighborhoods with more Hispanic and Asian residents are exposed to less and more violent crime, respectively, compared to neighborhoods with more White residents. However, this is only observed when not adjusting for the volume of visits points of interest receive; otherwise, the finding is reversed. This study offers valuable insights into potentially novel sources of racial disparities in exposure to violent crimes in everyday contexts, highlighting the need for further investigation.

Adolescent civic engagement: Lessons from Black Lives Matter.

In 2020, individuals of all ages engaged in demonstrations condemning police brutality and supporting the Black Lives Matter (BLM) movement. Research that used parent reports and trends commented on in popular media suggested that adolescents under 18 had become increasingly involved in this movement. In the first large-scale quantitative survey of adolescents' exposure to BLM demonstrations, 4,970 youth (meanage = 12.88 y) across the United States highlighted that they were highly engaged, particularly with media, and experienced positive emotions when exposed to the BLM movement. In addition to reporting strong engagement and positive emotions related to BLM demonstrations, Black adolescents in particular reported higher negative emotions when engaging with different types of media and more exposure to violence during in-person BLM demonstrations. Appreciating youth civic engagement, while also providing support for processing complex experiences and feelings, is important for the health and welfare of young people and society.

Highly public anti-Black violence is associated with poor mental health days for Black Americans.

Highly public anti-Black violence in the United States may cause widely experienced distress for Black Americans. This study identifies 49 publicized incidents of racial violence and quantifies national interest based on Google searches; incidents include police killings of Black individuals, decisions not to indict or convict the officer involved, and hate crime murders. Weekly time series of population mental health are produced for 2012 through 2017 using two sources: 1) Google Trends as national search volume for psychological distress terms and 2) the Behavioral Risk Factor Surveillance System (BRFSS) as average poor mental health days in the past 30 d among Black respondents (mean weekly sample size of 696). Autoregressive moving average (ARMA) models accounted for autocorrelation, monthly unemployment, season and year effects, 52-wk lags, news-related searches for suicide (for Google Trends), and depression prevalence and percent female (for BRFSS). National search interest varied more than 100-fold between racial violence incidents. Black BRFSS respondents reported 0.26 more poor mental health days during weeks with two or more racial incidents relative to none, and 0.13 more days with each log10 increase in national interest. Estimates were robust to sensitivity tests, including controlling for monthly number of Black homicide victims and weekly search interest in riots. As expected, racial incidents did not predict average poor mental health days among White BRFSS respondents. Results with national psychological distress from Google Trends were mixed but generally unsupportive of hypotheses. Reducing anti-Black violence may benefit Black Americans' mental health nationally.

Community exposure to gun homicide and adolescents' educational aspirations.

INTRODUCTION: Witnessing violence and violent victimization have detrimental effects on adolescents' emotional functioning and ability to envision and plan for their futures. However, research is limited on the impact of violence that occurs in adolescents' communities-whether or not it was witnessed or experienced firsthand. This paper investigated the associations between community exposure to gun homicide and adolescents' high school and college graduation aspirations. METHODS: We analyzed data from the Future of Families and Child Wellbeing Study (N = 3031), a cohort study of children born 1998-2000 in 20 large US cities, merged with incident-level data on deadly gun violence from the Gun Violence Archive (2014-2017). Outcomes were reported by adolescents (girls and boys) during wave 6 (2014-2017) of the study, conducted when the children were 15 years of age. We employed ordinary least squares regression, ordered logistic regression, and multilevel stratification to examine the average and heterogeneous impacts of community exposure to gun homicide on adolescents' educational aspirations. RESULTS: Community exposure to gun homicide was associated with reduced high school graduation aspirations, particularly among adolescents with the lowest risk of exposure to gun homicide. Gun homicide exposure was also associated with increased college graduation aspirations; this association was concentrated among adolescents with moderate-high risk of exposure. CONCLUSIONS: Given the importance of education for job opportunities and the better health that accompanies education and occupational attainment, preventing early exposure to gun violence and providing institutional supports to help adolescents facing adversity realize their goals is essential to their long-term health and success.

Parenting practices as a buffer in the relationship between exposure to community violence and bullying in Mexican adolescents.

Multiple studies have shown that adolescents exposed to community violence are likely to engage in bullying behaviors. However, we still need to understand which variables can help reduce the influence of community violence exposure (CVE) on bullying. To investigate this question, a study was conducted with a sample of 568 Mexican adolescents, comprising 276 (48.6%) males and 292 (51.4%) females aged 12 to 16 years old (M age = 13.7 years, SD = 0.82). The study examined how parental support (PS) and parental induction to justice sensitivity (JS) can moderate the relationship between CVE and bullying. The study used structural equation modeling with latent variables. The results showed that CVE was positively associated with bullying, whereas PS and the induction to perpetrator JS were negatively associated. The moderation analysis suggests that the relationship between CVE and bullying was weaker among adolescents who received high PS. On the other hand, low and high parental induction to JS had the same moderating effect. Based on the findings, parental practices are critical when developing preventive programs to reduce the harmful effects of CVE on bullying behavior.

Individual and environmental correlates of childhood maltreatment and exposure to community violence: Utilizing a latent profile and a multilevel meta-analytic approach.

BACKGROUND: Childhood maltreatment (CM) and exposure to community violence (ETV) are correlated with physical/mental health and psychosocial problems. Typically, CM and ETV are examined separately, by subtypes within category, or collapsed across both into one category of adversity. Consequently, research is limited in identifying subgroups of individuals with different amounts of exposure to both CM and ETV. Accordingly, we lack sufficient understanding of the extent to which problems associated with CM and ETV vary based on the amount (i.e. dose) of exposure to both of these experiences. METHODS: We used 20 samples (28,300 individuals) to estimate person-centered profiles of CM and ETV occurrence and co-occurrence within each sample. An individual data multilevel meta-analytic framework was used to determine the average effect size across samples for different profiles and conditional probability correlations within sociodemographic, neighborhood, health, mental health, and psychosocial domains. RESULTS: The profile characterized by high levels of CM and high levels of ETV correlated with stressful life events, depression and anxiety symptoms, and general indicators of externalizing behaviors. CM predominant profiles were associated with mental health diagnoses and treatment. ETV predominant profiles associated with risk-taking/violent behavior and neighborhood-level disadvantage. However, nuance based on the dose of CM or ETV was evident. CONCLUSIONS: It is important to identify subgroups based on the amount of exposure to CM and ETV. These subgroups have differential relationships with correlates across domains. Greater delineation and description of the lived experience will allow for more precision in addressing the burden of childhood adversity.

Reviewing the Literature on the Impact of Gun Violence on Early Childhood Development.

PURPOSE OF REVIEW: To examine the impacts of gun violence on early childhood development including early childhood mental health, cognitive development, and the assessment and treatment of survivors. RECENT FINDINGS: The literature reflects that gun violence exposure is often associated with significant mental health outcomes including anxiety, post-traumatic stress, and depression in older youth. Historically, studies have focused on adolescents and their exposures to gun violence through proximity to gun violence within their communities, neighborhoods, and schools. However, the impacts of gun violence on young children are less known. Gun violence has significant impacts on mental health outcomes of youth aged 0-18. Few studies focus specifically on how gun violence impacts early childhood development. In light of the increase in youth gun violence over the past three decades with a significant uptick since the onset of the COVID-19 pandemic, continued efforts are needed to better understand how gun violence impacts early childhood development.

Longitudinal Patterns of Multidimensional Violence Exposure and Adolescent Early Sexual Initiation.

Early sexual intercourse is associated with sexually transmitted infections, pregnancy, and depressive symptoms, and delay of intercourse allows adolescents opportunities to practice relationship skills (Coker et al., 1994; Harden, 2012; Kugler et al., 2017; Spriggs & Halpern, 2008). Thus, understanding predictors of early sexual intercourse is crucial. Prior research has suggested that violence exposure is associated with early initiation of sexual intercourse in adolescence (Abajobir et al., 2018; Orihuela et al., 2020). However, most studies have looked only at a single type of violence exposure. In addition, little research has examined longitudinal patterns of violence exposure in order to determine whether there are particular periods when the violence exposure may have the strongest impact on sexual behavior. Guided by life history and cumulative disadvantage theories, we use longitudinal latent class analysis and data from the Future of Families and Child Well-being Study (N = 3,396; 51.1% female, 48.9% male) to examine how longitudinal patterns of multiple types of violence exposures across ages 3 to 15 are associated with early sexual initiation in adolescence. Findings suggest that experiencing persistent physical and emotional abuse across childhood was associated with the greatest prevalence of early sexual initiation. Early exposure to violence was not consistently associated with greater likelihood of sexual initiation; instead, early abuse was more strongly associated with sexual initiation for boys, while late childhood abuse was more strongly associated for girls. These findings suggest that gender-sensitive programs are highly needed to address unique risk factors for boys' and girls' sexual behaviors.

Local exposure to school shootings and youth antidepressant use.

While over 240,000 American students experienced a school shooting in the last two decades, little is known about the impacts of these events on the mental health of surviving youth. Using large-scale prescription data from 2006 to 2015, we examine the effects of 44 school shootings on youth antidepressant use. Our empirical strategy compares the number of antidepressant prescriptions written by providers practicing 0 to 5 miles from a school that experienced a shooting (treatment areas) to the number of prescriptions written by providers practicing 10 to 15 miles away (reference areas), both before and after the shooting. We include month-by-year and school-by-area fixed effects in all specifications, thereby controlling for overall trends in antidepressant use and all time-invariant differences across locations. We find that local exposure to fatal school shootings increases youth antidepressant use by 21.4% in the following 2 y. These effects are smaller in areas with a higher density of mental health providers who focus on behavioral, rather than pharmacological, interventions.

Trauma exposure, posttraumatic stress, and identity content valences among Japanese adolescents.

INTRODUCTION: Theorists and a few empirical studies have suggested that traumatic experiences, posttraumatic stress disorder (PTSD), and complex PTSD (CPTSD) may affect identity development. However, existing studies have overlooked how adolescents' traumas are associated with the alignment of their identity with socio-cultural expectations, which is a crucial component of identity development. To address this gap, this study examined the associations of various types of potentially traumatic experiences and PTSD and CPTSD symptoms with the positive and negative valences of identity affected by desirable and undesirable images within socio-cultural contexts. METHODS: A cross-sectional survey of 341 adolescents (44.0% girls; Mage = 14.8, SD = 1.8) was conducted in Japan. RESULTS: Exposure to certain types of potentially traumatic events (e.g., family violence and physical attack) were related to high levels of negative identity elements, whereas none of the types were related to positive identity elements. The results also indicated that CPTSD-specific symptoms of disturbances in self-organization (DSO) were related to high levels of negative identity elements rather than PTSD. CONCLUSIONS: The findings expand upon related research by suggesting that adolescents' exposure to some types of traumatic events (e.g., family violence and physical attack) and posttraumatic DSO symptoms have the potential to disturb the alignment of their identities with socio-cultural expectations.

The comparative and cumulative impact of different forms of violence exposure during childhood and adolescence on long-term adult outcomes.

Violence exposure during childhood and adolescence is associated with a range of negative psychosocial outcomes. Research examining the impact of violence exposure has been limited by the compartmentalization into separate bodies of research (e.g., community violence, domestic violence). There is also a paucity of research examining long-term adult outcomes. Using a large and racially diverse sample (n = 754; male = 58%; Black = 46%), the current longitudinal study aimed to elucidate the comparative and cumulative effect of different types of violence exposure (witnessing vs. victimization) across different locations (home, school, neighborhood) in childhood and adolescence (lifetime through Grade 8) on long-term internalizing, externalizing, and attention problems; substance use; and intimate partner violence in adulthood (age 25). Victimization, but not witnessing violence, predicted all five adult outcomes. Specifically, being victimized at home was associated with the widest range of negative outcomes (internalizing, externalizing, and attention problems), while school victimization was associated with substance use. Further, when youth experienced multiple types of violence across multiple locations (cumulative violence exposure), they experienced a more diverse range of negative outcomes in adulthood (composite score). The current study highlights the stronger effects of violence exposure in more proximal contexts, and how these locations are important for emotional and behavioral development.

Making meaning of community violence among adolescents: Associations between exposure, pro-violence attitudes and psychological symptoms.

This study examined one type of adolescent meaning making (i.e., the development of beliefs about violence) and its association with reported mental health symptoms in a sample of youth exposed to community violence. Eighty-seven adolescents (age 11-18; 64.4% female) from a metropolitan city in the Northeast were recruited through Craigslist and recreation center postings and data collection occurred from 2009 to 2013. Participants completed self-reported measures of community violence exposure, attitudes toward violence, and psychological symptoms of depression and posttraumatic stress disorder [PTSD]. Bivariate correlations, hierarchical linear regressions, and mediation analyses examined the associations between exposure, beliefs about violence, and mental health symptoms. Self-reported pro-violence attitudes were positively correlated with depression symptoms (r = 0.32, p < 0.01) and PTSD (r = 0.45, p < 0.01). Pro-violence attitudes significantly mediated the relationship between community violence exposure and depression symptoms (95% confidence interval [CI] = 0.003-0.061) and PTSD symptoms (95% CI = 0.046-0.260). Preliminary findings suggest that meaning making through the development of pro-violence attitudes may not protect against symptoms of PTSD and depression among youth. Findings can inform the integration of meaning making processes into community mental health interventions for youth.

Depression and post-traumatic stress during major social unrest in Hong Kong: a 10-year prospective cohort study.

BACKGROUND: Hong Kong has been embroiled in increasingly violent social unrest since June, 2019. We examined the associated population mental health burden, risk factors, and health-care needs. METHODS: In a population-based prospective cohort, adult participants aged 18 years or older were assessed at nine timepoints from 2009. Probable depression was measured using the Patient Health Questionnaire-9 (score ≥10) and suspected post-traumatic stress disorder (PTSD) by the PTSD Checklist-Civilian Version (score ≥14), plus direct exposure to traumatic events related to the ongoing social unrest. We used multivariable logistic regression to identify factors associated with both outcomes, adjusting for doctor-diagnosed depression or anxiety disorders before the unrest. On the basis of routine service statistics and respondents' intention to seek professional care, we projected the number of additional ambulatory specialist psychiatric visits required. FINDINGS: After the two baseline surveys, we followed up random subsets of 1213-1736 adults at each timepoint. Probable depression was reported by 11·2% (95% CI 9·8-12·7) of participants in 2019, compared with 1·9% (1·6-2·1) during 2009-14 and 6·5% (5·3-7·6) in 2017 after the Occupy Central Movement and before the current unrest. Prevalence of suspected PTSD in 2019 was estimated to be 12·8% (11·2-14·4). Age, sex, educational attainment, or household income were not associated with either outcome, whereas heavy social media use (≥2 h per day) was associated with both. Political attitude or protest participation was not associated with probable depression, but neutrality towards the extradition bill approximately halved the risk of suspected PTSD. Family support mitigated against probable depression. We estimated that the mental health burden identified would translate into roughly an excess 12% service requirement to the public sector queue or equivalent. INTERPRETATION: We have identified a major mental health burden during the social unrest in Hong Kong, which will require substantial increases in service surge capacity. Health-care and social care professionals should be vigilant in recognising possible mental health sequelae. In a world of increasing unrest, our findings might have implications for service planning to better protect population mental health globally. FUNDING: Research Grants Council, University Grants Committee of Hong Kong, Hong Kong Jockey Club Charities Trust.

A focus on adolescence to reduce neurological, mental health and substance-use disability.

Globally, there is a crucial need to prioritize research directed at reducing neurological, mental health and substance-use disorders in adolescence, which is a pivotal age for the development of self-control and regulation. In adolescence, behaviour optimally advances towards adaptive long-term goals and suppresses conflicting maladaptive short-lived urges to balance impulsivity, exploration and defiance, while establishing effective societal participation. When self-control fails to develop, violence, injury and neurological, mental health and substance-use disorders can result, further challenging the development of self-regulation and impeding the transition to a productive adulthood. Adolescent outcomes, positive and negative, arise from both a life-course perspective and within a socioecological framework. Little is known about the emergence of self-control and regulation in adolescents in low- and middle-income countries where enormous environmental threats are more common (for example, poverty, war, local conflicts, sex trafficking and slavery, early marriage and/or pregnancy, and the absence of adequate access to education) than in high-income countries and can threaten optimal neurodevelopment. Research must develop or adapt appropriate assessments of adolescent ability and disability, social inclusion and exclusion, normative development, and neurological, mental health and substance-use disorders. Socioecological challenges in low- and middle-income countries require innovative strategies to prevent mental health, neurological and substance-use disorders and develop effective interventions for adolescents at risk, especially those already living with these disorders and the consequent disability.

Temporal Stability of Self-Reported Trauma Exposure on the Life Events Checklist for DSM-5.

The Life Events Checklist for DSM-5 (LEC-5) is a comprehensive screening instrument used to detect exposure to a range of potentially traumatic events. Despite its widespread use, research assessing the psychometric properties of scores on the LEC-5-and trauma exposure more broadly-is scarce. Using a large sample of undergraduate students (N = 1,013), we sought to evaluate the reliability of trauma exposure reporting on the LEC-5 across 8- (N = 379) and 12-week (N = 343) intervals. Reliability estimates were examined for trauma exposure type (e.g., experiencing, witnessing), traumatic event type (e.g., sexual assault), and index trauma (i.e., "worst event") reporting. Reliability was more stable for events that were directly experienced, intraclass correlation coefficients (ICCs) = .62-64, than events that were witnessed, ICCs = .47-.52, or learned about, ICCs = .48-.53. Test-retest agreement was fair to good for reports of sexual assault, physical assault, transportation accidents, natural disasters, and other sexual experiences, κs = .49-.72, but only when individuals directly experienced these events. By contrast, across both assessment intervals, the agreement was attenuated, all κs < .40, for events that individuals witnessed or learned about regardless of event type. For index events, only sexual assault and sudden accidental or violent deaths were consistently reported with a fair or better agreement, κs = .42-.64. These findings suggest that reliable trauma reporting varies largely based on the nature of the traumatic event, yielding important implications for the assessment of DSM-5 Criterion A and posttraumatic stress disorder.

PTSD Coach Online-Arabic: A Randomized Controlled Pilot Trial to Examine Feasibility, Acceptability, and Preliminary Effectiveness.

The Egyptian Revolution of 2011 resulted in high-level exposure to sociopolitical violence, placing a large burden on the mental health care system that cannot be effectively met given the small number of available providers in Egypt. We conducted a nonblinded, randomized controlled pilot trial of an online, self-directed tool for managing posttraumatic stress symptoms (PTSS). The study aimed to evaluate the feasibility, acceptability, and preliminary effectiveness of the PTSD Coach Online-Arabic. Trauma-exposed Egyptian adults with clinically significant PTSS (N = 87; intervention group: n = 41) completed assessments at baseline, weekly over the treatment period, posttest, and 3-month follow-up. Of participants who completed weekly surveys, 88.9% used the program; 22.0% of participants reported regular, weekly use. Most tools received good likeability and perceived benefit scores, but lower perceived benefit scores on three tools suggest that some content may require additional adaptation. Intent-to-treat analyses using multilevel modeling with multiple imputation to account for missing data were conducted. Effect sizes for PTSS were below the cutoff for small effects at posttest, d = -0.14, but demonstrated a small positive effect at 3-months, d = -0.25. There was a small positive effect of treatment on anxiety at posttest, d = -0.37, and a medium effect at 3-month follow-up, d = -0.49. Treatment effects for depressed mood were below the cutoff for small effects at posttest and 3-months, ds = -0.14 and -0.18. These findings suggest that the PTSD Coach Online-Arabic may be a promising supplemental resource for support in this setting.

Posttraumatic Distress and Treatment Barriers Among Former Gang Members: Implications for Improving Access to Traumatic Stress Resources in Marginalized Populations.

Limited research has examined the links among violent victimization, mental health, and service utilization among gang-involved individuals. This mixed-methods preliminary study examined narratives of psychiatric distress, current psychiatric morbidity, and mental health treatment experiences among a sample of former gang members (N = 32; M age = 44.4 years, 87.5% male; 56.3% Hispanic or Latino, 31.3% African American). Participants completed online questionnaires to assess trauma exposure and current psychiatric symptoms as well as a semistructured interview to examine histories of psychiatric distress and mental health treatment. Participants reported exposure to an average of 10.2 discrete traumatic events (range: 3-21). On average, participants reported exposure to five to six community violence-related events, ranging from never or one time up to monthly and weekly exposure. Participants generally described histories of depression, anxiety, posttraumatic stress disorder (PTSD), and substance abuse, although a thematic analysis revealed PTSD symptoms predominated the psychiatric distress described, including symptoms related to intrusions, avoidance, negative alterations in cognitions and mood, and alterations in arousal. Grounded theory analysis revealed barriers to traditional models of mental health treatment included self-isolation, gang rules, and social stigma, especially in the context of interpersonal disconnect with providers. Given conditions of limited resources to access treatment, participants engaged in peer support services, which may have reduced their psychiatric distress to currently low levels. Implications for understanding these notable findings of recovery and resilience for some individuals and building trauma-informed communities that improve access to traumatic stress resources for marginalized populations are discussed.

Examination of the Factor Structure and Correlates of the Perceived Military Healthcare Stressors Scale.

The current study evaluated the factor structure, reliability estimates, correlates, and predictive utility of the Perceived Military Healthcare Stressor Scale (PMHSS) in a sample of active duty military medical personnel (N = 1,131) deployed to Joint Base Balad in Iraq. The sample was composed of an approximately even split of male (51.2%) and female (48.8%) participants who ranged in age from 18 to 60 years. The PMHSS is a 21-item measure that was designed to assess the impact of specific medical stressors that military healthcare providers may encounter while deployed. An exploratory factor analysis of the PMHSS revealed the presence of two distinct factors: trainable and futility stressors. Confirmatory factor analysis showed that a bifactor model best represented the data, with all items loading higher on the general factor relative to their specific subscale factors. Evidence of partial scalar invariance by gender was found. The PMHSS was significantly correlated with several convergent measures, including assessments of posttraumatic stress disorder (PTSD), depression severity, distress due to both combat exposure and general deployment-related concerns, and positive affect, rs = .30-.59. PMHSS scores were more strongly correlated with PTSD and depression in women than in men, and they provided incremental validity in predicting convergent measures over and above other related constructs. Healthcare-specific stressors are an understudied area, and this study provides new insights into how deployment-related caregiving stress may impact deployed military medical personnel independently of the impact of combat experiences.