Canadian military personnel's population attributable fractions of mental disorders and mental health service use associated with combat and peacekeeping operations.

OBJECTIVES: We investigated mental disorders, suicidal ideation, self-perceived need for treatment, and mental health service utilization attributable to exposure to peacekeeping and combat operations among Canadian military personnel.

METHODS: With data from the Canadian Community Health Survey Cycle 1.2 Canadian Forces Supplement, a cross-sectional population-based survey of active Canadian military personnel (N = 8441), we estimated population attributable fractions (PAFs) of adverse mental health outcomes.

RESULTS: Exposure to either combat or peacekeeping operations was associated with posttraumatic stress disorder (men: PAF = 46.6%; 95% confidence interval [CI] = 27.3, 62.7; women: PAF = 23.6%; 95% CI = 9.2, 40.1), 1 or more mental disorder assessed in the survey (men: PAF = 9.3%; 95% CI = 0.4, 18.1; women: PAF = 6.1%; 95% CI = 0.0, 13.4), and a perceived need for information (men: PAF = 12.3%; 95% CI = 4.1, 20.6; women: PAF = 7.9%; 95% CI = 1.3, 15.5).

CONCLUSIONS: A substantial proportion, but not the majority, of mental health-related outcomes were attributable to combat or peacekeeping deployment. Future studies should assess traumatic events and their association with physical injury during deployment, premilitary factors, and postdeployment psychosocial factors that may influence soldiers' mental health.