External locus-of-control partially mediates the association between cumulative trauma exposure and posttraumatic stress symptoms among adolescents from diverse background

Background and Objectives Locus of control (LOC) is a modifiable mediator of symptoms of posttraumatic stress disorder (PTSD) among traumatized individuals and a potential target of intervention. Compared with studies involving adults, the potential mediation effect of LOC on PTSD symptoms among trauma-exposed children and adolescents is relatively under-explored. This study, therefore, assessed the mediation effects of LOC on the association between lifetime cumulative trauma and PTSD symptoms among a large cohort of adolescents from different cultural background. Design Cross-sectional study. Methods LOC was determined using the Multi-Dimension Locus of Control Scale; Posttraumatic stress symptoms using the UCLA PTSD Reaction Index; and other significant negative life events using the Life Events Checklist. Results Among 3826 adolescents who completed the study, external LOC explained 24% of variance (R (2) = .24; F-2,F-3823 = 619.01; p < .01) in PTSD symptoms and had significant indirect effect on the relationship between self-reported cumulative traumatic event exposure and PTSD symptoms (ss = .14; 95% BC CI [.10, .20]). Moderated mediation results showed significant potentiation of the moderation effects among older adolescents; boys; and those from more affluent families. Conclusions The study further strengthened the hitherto limited evidence that external LOC partially mediate the relationship between cumulative trauma exposure and PTSD symptoms among adolescents.