PTSD, Depressive Symptoms Mediate Relationship Between Insomnia and Risk for Suicidal Behavior
Both insomnia and PTSD symptoms were significantly associated with depressive symptoms.
Insomnia may be associated with increased posttraumatic stress disorder (PTSD) and depressive symptoms, which may increase the risk for suicide. These findings were reported in the Journal of Affective Disorders,
A total of 545 self-identified veterans were administered a set of questionnaires, including a standard demographic questionnaire, the PTSD Checklist-Military measure, the Multidimensional Health Profile-Depression Scale, the Insomnia Severity Index, the Interpersonal Needs Questionnaire, and the Suicide Behaviors Questionnaire-Revised. The questionnaires were administered online and measured demographic variables, PTSD and depressive symptoms, insomnia severity, thwarted belongingness and perceived burdensomeness, and risk for suicidal behaviors, respectively. Pearson's product-moment correlations and serial mediation were used to examine associations among insomnia symptoms, PTSD symptoms, depressive symptoms, thwarted belongingness, perceived burdensomeness, and risk for suicidal behavior.
The survey was completed in its entirety by 72% (n=392) of the initial sample, among whom 70% were men and 88% were white. The mean age of participants was 50 years, and 50% scored 15 or above on the Insomnia Severity Index, indicating moderate to severe sleep problems. On the full PTSD Checklist-Military measure, 42% scored at or above the cutoff for military populations. In addition, on the Suicide Behaviors Questionnaire-Revised, 77% scored at or above the general population cutoff (≥7), and 45% scored at or above the cutoff for psychiatric inpatients (≥8). Per serial mediation, the model for risk for suicidal behavior with thwarted belongingness was significant (P <.001) and accounted for 29% of the variance in risk for suicidal behavior.
In this model, insomnia symptoms were significantly associated with PTSD symptoms (P <.001). Also, both insomnia and PTSD symptoms were significantly associated with depressive symptoms (both P <.001). Depressive symptoms and thwarted belongingness were significantly associated with risk for suicidality (P <.01 and P <.001, respectively), but PTSD symptoms and insomnia symptoms were not. As such, indirect effects for insomnia symptoms on suicidality were significant; this outcome was not found for direct effects. A similar trend was observed in the model for risk for suicidal behavior with perceived burdensomeness, which was significant (P <.001) and accounted for 35% of the variance in risk for suicidal behavior. In this model, direct effects for insomnia symptoms on suicidality were again not significant, although indirect effects were. In addition, depression and perceived burdensomeness were each significantly associated with suicidal behavior risk (P =.01 and P <.001, respectively).
These data highlight the effect of insomnia on factors that both directly and indirectly increase suicidality risk. Specifically, insomnia is associated with depressive symptoms, thwarted belongingness, and perceived burdensomeness, which each directly affect suicidal behavior. Insomnia is also associated with increased PTSD symptom severity, which has an indirect effect on suicidality through the aforementioned factors. Taken together, these results suggest that the symptoms of insomnia are associated with psychiatric symptoms, which in turn are directly implicated in increased suicidal behaviors. Further research is necessary to explore these associations and investigate effective methods of intervention.
Britton PC, McKinney JM, Bishop TM, Pigeon WR, Hirsch JK. Insomnia and risk for suicidal behavior: a test of a mechanistic transdiagnostic model in veterans. J Affect Disord. 2018;245:412-418.