The association among insomnia symptom severity, comorbid symptoms, and suicidal ideation in two veteran cohorts meeting diagnostic criteria for insomnia disorder.

OBJECTIVE: Examine the association between insomnia symptom severity and suicidal ideation (SI), after adjusting for clinical comorbidity in veterans meeting diagnostic criteria for insomnia disorder. METHODS: Secondary data analyses of psychometrically validated baseline assessments of depression, posttraumatic stress disorder (PTSD), and anxiety symptoms from two online insomnia intervention randomized clinical trials (n = 232; n = 80) were conducted. Multiple linear regression was used to determine the association between insomnia symptom severity and SI, after controlling for clinical comorbidity and demographics. RESULTS: Insomnia symptom severity was significantly correlated with comorbid depression, PTSD, and anxiety symptoms in both cohorts and significantly correlated with SI in one. After controlling for demographics and clinical comorbidity, insomnia symptom severity was not significantly associated with SI in linear regression models. CONCLUSION: Findings extend insomnia-suicide research by providing evidence that insomnia symptom severity may not confer a unique risk for SI above comorbid mental health symptoms in veterans meeting diagnostic criteria for insomnia disorder.