UC Irvine

Background: The mental health burden of posttraumatic stress disorder (PTSD) is high in U.S. military samples. Social support is one of the most robust protective factors against PTSD and a recent meta-analysis indicates that this relationship is even stronger in military samples compared to civilian samples. Yet no meta-analyses have explored factors impacting this association in veterans and military service members (VSMs). Objective: The current meta-analysis examined demographic, social support, and military characteristics that may moderate the relationship of PTSD severity and social support among U.S. VSMs. Method: A search identified 37 cross-sectional studies, representing 38 unique samples with a total of 18,766 individuals. Results: The overall random effects estimate was -.33 (95% CI: -.38, -.27, Z = -10.19, p <.001), indicating that lower levels of social support were associated with more severe PTSD symptoms. PTSD measures based on the Diagnostic and Statistical Manual (DSM)-III had a larger effect size than measures based on DSM-IV or DSM-5. The social support source was a significant moderator such that support perceived from non-military sources was associated with a larger effect size than support perceived from military sources. This finding held after accounting for covariates. Deployment-era, timing of social support, and age were also significant moderators, but were no longer significantly associated with effect size after adjusting for covariates. Although previous meta-analyses have shown social negativity to be more impactful than positive forms of social support, there were too few studies conducted to evaluate social negativity in moderator analyses. Conclusion: Results suggest that social support received from civilians and in the home environment may play a greater protective role than social support received from military sources on long-term PTSD symptom severity. The literature on social support and PTSD in U.S. VSMs would be strengthened by studies examining the association of social negativity and PTSD symptoms.