The Mediating Effects of Social Support and Locus of Control on the Relationship between Post-Traumatic Stress and Depressive Symptoms in a Jamaican University Sample

Background: The increasing rate of comorbid posttraumatic stress and depressive symptoms among young adults presents a unique symptom presentation and challenges to treatment. The current study examined psychosocial barriers--external locus of control-- and facilitators-- social support-- in the posttraumatic stress and depressive symptoms association.

Methods: The current cross-sectional study was conducted among 701 Jamaican university participants, ages 18-30 years. Participants completed self-report measures of general demographic information as well as target variables which include the CES-D-10, Sense of control (external and internal locus of control), Short screening scale for DSM-IV posttraumatic stress disorder and social support measures.

Results: Majority of the sample was female (76.2%; n=534); and slightly more than half of the sample self-identified as Black/African ancestry (59.7%). External locus of control (LOC) partially mediated the relationship between posttraumatic stress and depressive symptoms, external locus of control (LOC) had a greater mediation magnitude than social support in the posttraumatic stress-depressive symptoms association (Indirect Effect=0.133, 95% CI-0.075-0.211). In post-hoc analyses women appeared more highly traumatized than their male counterparts (14.3%, χ² =8.032, p=0.005). The sub-sample of highly traumatized individuals reported higher levels of depression, posttraumatic stress symptoms, external LOC, and lower levels of social support and internal LOC than did individuals with lower levels of trauma.

Conclusion: Contrary to previous research, our findings indicate that external LOC partially mediated the relationship between posttraumatic stress and depressive symptoms among a Jamaica university sample more so than social support. These findings therefore suggest that psychosocial treatments should consider locus of control focused interventions or skill building for young adults who suffer from posttraumatic stress and depressive symptoms.