As self-injurious thoughts and behaviors (SITB) remain a pressing public health concern, research continues to focus on risk factors, such as posttraumatic stress disorder (PTSD). Network analysis provides a novel approach to examining the PTSD-SITB relationship. This study utilized the network approach to elucidate how individual PTSD symptoms may drive and maintain SITB.

We estimated cross-sectional networks in two samples of trauma-exposed adults (Sample 1: N = 349 adults; Sample 2: N = 1307 Veterans) to identify PTSD symptoms that may act as bridges to SITB. Additionally, we conducted a cross-lagged panel network in Sample 2 to further clarify the temporal relationship between PTSD symptoms and SITB during a 2-year follow-up. Finally, in both samples, we conducted logistic regressions to examine the utility of PTSD symptoms in prospectively predicting SITB, over a 15-day period (Sample 1) and over a 2-year period (Sample 2), allowing us to examine both short- and long-term prediction.

Two PTSD symptoms (i.e. negative beliefs and risky behaviors) emerged as highly influential on SITB in both cross-sectional networks. In the cross-lagged panel network, distorted blame emerged as highly influential on SITB over time. Finally, risky behaviors, unwanted memories, and psychological distress served as the strongest predictors of SITB across the two samples.

Overall, our results suggest that treatments targeting negative beliefs and risky behaviors may prevent SITB in community and Veteran populations, whereas treatments targeting distorted blame and unwanted memories may help reduce SITB for individuals with a history of combat trauma.

Over half of individuals with eating disorders experience suicidal ideation at some point in their lives, yet few longitudinal studies have examined predictors of ideation in this at-risk group. Moreover, prospective research has focused on relatively distal or trait-level factors that are informative for distinguishing who is most at risk but not when. Little is known about more proximal or state-level risk factors that fluctuate within an individual, which is critical for determining when a person is most likely to engage in suicidal behaviors.

Women (N = 97) receiving treatment for their eating disorder completed questionnaires weekly to assess suicidal ideation and interpersonal constructs (i.e. perceived burdensomeness, thwarted belongingness) theorized to be proximal predictors of suicidal desire. Longitudinal multilevel models were conducted to examine both within- and between-person predictors of suicidal ideation across 12 weeks of treatment.

Statistically significant within-person effects for burdensomeness (β = 0.06; p < 0.001) indicate that when individuals have greater feelings of burdensomeness compared to their own average, they also experience higher suicidal ideation. We did not find any significant influence of thwarted belongingness or the interaction between burdensomeness and belongingness on suicidal ideation.

This study was the first to examine dynamic associations between interpersonal constructs and suicidal ideation in individuals with eating disorders. Results are only partially consistent with the Interpersonal Theory of Suicide and suggest that short-term changes in burdensomeness may impact suicidal behavior in individuals with eating disorders.