Background: Betrayal traumas have a particularly deleterious effect on mental health. Although social support is a robust predictor of posttraumatic stress disorder (PTSD) symptom severity, it is not clear what factors may impact this relationship among betrayal trauma survivors. Objective: This study sought to describe the association between social support and PTSD symptom severity among survivors of betrayal trauma and examine whether methodological, sample, trauma, and social support characteristics moderated this association. Method: A comprehensive search identified 29 studies that assessed the cross-sectional association between PTSD symptom severity and social support among 6,510 adult betrayal trauma survivors. Results: The average effect size (r = -.25; 95% CI: -.30, -.20) was small to medium, with significant heterogeneity between studies (I² = 71.86). The association between PTSD and social support was stronger when the trauma was perpetrated by a romantic partner compared to mixed perpetrators, even after accounting for covariates. There was also a significant effect of support type depending on whether the support was provided in the context of trauma disclosure. Specifically, positive reactions to trauma disclosure were not associated with PTSD symptoms whereas general positive social support (not disclosure focused) was associated with fewer PTSD symptoms. Negative reactions to trauma disclosure were associated with more PTSD symptoms. None of the included studies measured general negative social support outside of trauma disclosure. Conclusions: Our findings suggest that social support may be a particularly important buffer against PTSD symptoms when experiencing traumatic betrayal by an intimate partner. Additionally, our results suggest that social support interventions for those experiencing betrayal trauma should focus on reducing negative responses to disclosure and bolstering general satisfaction with social support.

Social support is one of the most robust predictors of posttraumatic stress disorder (PTSD). Yet, little is known about factors that moderate the relationship between social support and PTSD symptom severity. This meta-analysis estimated the overall effect size of the relationship between self-reported social support and PTSD severity and tested meaningful demographic, social support, and trauma characteristics that may moderate this association using both cross-sectional and longitudinal effect sizes. A comprehensive search identified 139 studies with 145 independent cross-sectional effect sizes representing 62,803 individuals and 37 studies with 38 independent longitudinal effect sizes representing 25,792 individuals. Study samples had to comprise trauma-exposed, nonclinical adult populations to be included in the analysis. Cross-sectional and longitudinal analyses revealed a near medium overall effect size (rcross = -.27; 95% CI [-.30, -.24]; rlong = -.25; 95% CI [-.28, -.21]) with a high degree of heterogeneity (cross-sectional I2 = 91.6, longitudinal I2 = 86.5). Both cross-sectional and longitudinal moderator analyses revealed that study samples exposed to natural disasters had a weaker effect size than samples exposed to other trauma types (e.g., combat, interpersonal violence), studies measuring negative social reactions had a larger effect size than studies assessing other types of social support, and veteran samples revealed larger effect sizes than civilian samples. Several other methodological and substantive moderators emerged that revealed a complex relationship between social support and PTSD severity. These findings have important clinical implications for the types of social support interventions that could mitigate PTSD severity. (PsycInfo Database Record (c) 2021 APA, all rights reserved).