Suicide attempts and mental health diagnoses in combat-injured service members: A retrospective cohort study.

INTRODUCTION: Examinations of risk factors for suicide attempt in United States service members at high risk of mental health diagnoses, such as those with combat injuries, are essential to guiding prevention and intervention efforts. METHODS: Retrospective cohort study of 8727 combat-injured patients matched to deployed, non-injured patients utilizing Department of Defense and Veterans Affairs administrative records. RESULTS: Combat injury was positively associated with suicide attempt in the univariate model (HR = 1.75, 95% CI 1.5-2.1), but lost significance after adjustment for mental health diagnoses. Utilizing Latent Transition Analysis in the combat-injured group, we identified five mental/behavioral health profiles: (1) Few mental health diagnoses, (2) PTSD and depressive disorders, (3) Adjustment disorder, (4) Multiple mental health comorbidities, and (5) Multiple mental health comorbidities with alcohol use disorder (AUD). Multiple mental health comorbidities with AUD had the highest suicide attempt rate throughout the study and more than four times that of Multiple mental health comorbidities in the first study year (23.4 vs. 5.1 per 1000 person years, respectively). CONCLUSION: Findings indicate that (1) combat injury's impact on suicide attempt is attenuated by mental health and (2) AUD with multiple mental health comorbidities confers heightened suicide attempt risk in combat-injured service members.