Insomnia and risk for suicidal behavior: A test of a mechanistic transdiagnostic model in veterans

Background: Insomnia has been shown to have direct and indirect associations with suicidal ideation, attempts, and death in U.S. military and veteran populations. However, transdiagnostic models of insomnia and psychopathology have not been used to examine the contribution of psychopathology. Method: The present study is a secondary analysis examining the associations among insomnia symptoms, posttraumatic stress disorder (PTSD) and depressive symptoms, interpersonal theory of suicide variables, and risk for suicidal behavior in community veterans (n=392). Serial mediation was used to test sequential associations, allowing for examination of direct and indirect associations. Results: The model with insomnia, PTSD, and depressive symptoms, and thwarted belongingness, accounted for 29% of the variance in risk. Insomnia symptoms had an indirect association through PTSD and depressive symptoms, and thwarted belongingness. The model with insomnia, PTSD, and depressive symptoms, and perceived burdensomeness accounted for 35% of the variance in risk. Insomnia symptoms had an indirect association through PTSD and depressive symptoms, and perceived burdensomeness. Limitations: Data are cross-sectional, precluding the testing of causal associations. Conclusions: In veterans, insomnia symptoms may be associated with increased PTSD and depressive symptoms, which may be associated with increased risk for suicidal behavior directly and indirectly through relationship disruptions.