PTSD and Suicidal Ideation: An Application of the Interpersonal-Psychological Theory of Suicide

Abstract

The relationship between posttraumatic stress disorder (PTSD) and passive suicidal ideation (P-SI) is well established, but the mechanisms underlying it are not well understood (Panagioti, Gooding, & Tarrier, 2012).This study sought to enhance understanding of the PTSD/P-SI relationship using the interpersonal theory of suicide (IPTS; Joiner, 2005) as a conceptual framework. It was hypothesized that the strongest relationship between individual PTSD clusters and P-SI would be found for the emotional numbing symptoms, but that this relationship would be fully mediated by one or both IPTS constructs specified as proximal causes for SI: thwarted belongingness and perceived burdensomeness. Participants were trauma-exposed college students (N = 334). Hypotheses were tested using structural equation modeling while controlling for gender and sadness. Although the numbing cluster had the strongest bivariate relationship with P-SI, full mediation through one or both IPTS constructs was not observed. Instead, numbing and reexperiencing were both directly related to P-SI, and all PTSD clusters had indirect relationships with P-SI, partially mediated through one or both IPTS constructs. Results, while not entirely consistent with hypotheses, support the utility of the IPTS for understanding P-SI among those with PTSD, and point to a unique relationship between P-SI and numbing.