PTSD symptoms and suicide ideation: Testing the conditional indirect effects of thwarted interpersonal needs and using substances to cope

• Perceived burdensomeness mediated the relation between PTSD symptoms and suicide ideation.
• Thwarted belongingness did not mediate the relation between PTSD symptoms and suicide ideation.
• Using substances to cope moderated the above relation.

Posttraumatic stress disorder (PTSD) symptoms and substance use have been associated with increased suicide ideation, but have rarely been examined within a larger theoretical context of suicide risk. The interpersonal theory of suicide posits that feeling disconnected from others (i.e., thwarted belongingness) and feeling like a burden on others (i.e., perceived burdensomeness) are associated with increased suicide ideation. We hypothesized that perceived burdensomeness and thwarted belongingness would mediate the relation between PTSD symptoms and suicide ideation, and that using substances to cope would moderate these relations. Participants were 254 college students reporting exposure to potentially traumatic experiences. Findings from a moderated mediation analysis indicated that perceived burdensomeness, but not thwarted belongingness, mediated the relation between PTSD symptoms and suicide ideation, and using substances to cope moderated this relation. Therapeutic interventions aimed at reducing suicide ideation might benefit from decreasing perceived burdensomeness and the use of substances to cope.