Classifying childhood war trauma exposure: latent profile analyses of Sierra Leone’s former child soldiers Shaobing Su, 1 Rochelle L. Frounfelker, 2 Alethea Desrosiers, 1 Robert T. Brennan, 1,3 Jordan Farrar, 1 and Theresa S. Betancourt 1 1 Research Program on Children and Adversity, Boston College School of Social Work, Chestnut Hill, MA, USA; 2 Division of Social and Transcultural Psychiatry, Department of Psychiatry, McGill University, Montreal, QC, Canada; 3 Women’s Study Research Center, Brandeis University, Waltham, MA, USA Background: Former child soldiers are at elevated risk for mental health problems (e.g., traumatic stress, emotion dysregulation, and internalizing and externalizing problems). To examine which groups of former child soldiers are more likely to have difficulties with emotion regulation, interpersonal relationships, and mental health postconflict, we explored patterns of war trauma exposure and their effects on subsequent mental health problems among former child soldiers in Sierra Leone. Methods: Participants were 415 (23.86% female) Sierra Leonean former child soldiers participating in a 15-year, four-wave longitudinal study. At T1 (2002), 282 former child soldiers (aged 10–17) were recruited. T2 (2004) included 186 participants from T1 and an additional cohort of self-reintegrated former child soldiers (NT2 = 132). T3 (2008) and T4 (2016/2017) participants were youth enrolled in previous waves (NT3 = 315; NT4 = 364). Latent profile analysis (LPA) was used to classify participants based on the first-time reports of eight forms of war exposure (separation and loss of assets, parental loss, loss of loved ones, witnessing violence, victimization, perpetrating violence, noncombat activities, and deprivation). ANOVA examined whether patterns of war exposure were associated with sociodemographic characteristics and mental health outcomes between T1 and T4. Results: LPA identified two profiles: higher exposure versus lower exposure, using cumulative scores of eight forms of war-related trauma exposure. The ‘higher war exposure’ group comprised 226 (54.5%) former child soldiers and the ‘lower war exposure’ group included 189 (45.5%). Significantly higher levels of violence-related and combat experiences characterized the group exposed to more traumatic events. The ‘higher war exposure’ group reported more PTSD symptoms at T2, more hyperarousal symptoms across all waves, and more difficulties in emotion regulation at T4. Conclusions: Former child soldiers exposed to higher levels of war-related traumatic events and loss should be prioritized for mental health services immediately postconflict and as they transition into adulthood. Keywords: Childhood war trauma; former child soldiers; latent profile analysis; mental health outcomes; PTSD. Introduction Child exposure to conflict-related violence, particu- larly the involvement of children with armed groups, usually by force or abduction (i.e., ‘child soldiers’), is a serious humanitarian issue (United Nations, 2013a; Wolf, Prabhu & Carello, 2019), and the number of child soldiers continues to increase (NATO, 2011; United Nations, 2013b, 2018). Many child soldiers report being forced to perpetrate violence and witnessing and/or being victimized by violent acts, including physical injury, rape, torture, and killing (Betancourt, Agnew-Blais, Gilman, Wil- liams, & Ellis, 2010; Betancourt, Brennan, Rubin- Smith, Fitzmaurice, & Gilman, 2010; Betancourt et al., 2020). Layne et al. (2014) have articulated a concept of ‘risk factor caravans’ in which exposure to risks to psychosocial well-being, such as traumatic events, co-occur, accumulate, and cascade over time to negatively impact youth development and health outcomes throughout the lifespan. Former child soldiers may be at particularly high risk for both short- and long-term mental health problems and impairments in social functioning (Betancourt, McBain, Newnham, & Brennan, 2014; Betancourt, Newnham, McBain, & Brennan, 2013; Betancourt et al., 2020). Although the association between childhood war exposure and adverse mental health outcomes is well documented (Attanayake et al., 2009; Betancourt, Borisova, Soudiere, & Wil- liamson, 2011; Slone & Man, 2016), the longer-term, cumulative and cascading effects of multiple and/or different types of war traumas on mental health over time are less studied. Further research is needed to better understand which groups of former child soldiers are more likely to have difficulties with emotion regulation, interpersonal relationships, and mental health postconflict. Previous studies have shown that not all former child soldiers report sustained mental health prob- lems in postconflict settings (e.g., Betancourt, Bren- nan, & Rubin-Smith et al., 2010; Betancourt, McBain, Newnham, et al., 2013; Betancourt et al., 2020; Punam€ aki, Palosaari, Diab, Peltonen, & Qouta, 2015). Research has identified patterns of postconflict social factors (e.g., trajectories of stigma, community, and family acceptance) that differenti- ated long-term mental health among former child soldiers (Betancourt et al., 2020). Given that former Conflict of interest statement: No conflicts declared. © 2020 Association for Child and Adolescent Mental Health Published by John Wiley & Sons Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main St, Malden, MA 02148, USA Journal of Child Psychology and Psychiatry **:* (2020), pp **–** doi:10.1111/jcpp.13312