Understanding mental health disorder diagnosis and treatment seeking among active-duty military personnel is a topic with both clinical and policy implications. It has been well documented in military populations that individual-level military experience, including deployment history and combat exposure, influences mental health outcomes, but the impact of unit-level factors is less well understood. In the current study, we used administrative longitudinal data to examine a comprehensive set of unit- and individual-level predictors of posttraumatic stress disorder (PTSD), non-PTSD anxiety disorders, depressive disorders, and overall mental health diagnoses among Army and Marines Corps personnel. Using Cox survival models for time-dependent variables, we analyzed time from military accession (between January 1, 2001 and December 31, 2011) until first mental health diagnosis for 773,359 soldiers and 332,093 Marines. Prior diagnosis of a substance abuse disorder during one's military career, hazard ratios (HRs) = 1.68-3.10, and cumulative time spent deployed, HRs = 1.11-2.04, were the most predictive risk factors for all outcomes. Male sex, HRs = 0.35-0.57, and officer rank, HRs = 0.13-0.23, were the most protective factors. Unit-level rate of high deployment stress was a small but significant predictor of all outcomes after controlling for individual-level deployment history and other predictors, HRs = 1.01-1.05. Findings suggest both unit- and individual-level risk and protective factors of mental health diagnoses associated with treatment seeking. Clinical, including mental health assessment and management, and policy implications related to the military environment and the individual as it relates to mental health disorders are discussed.
© 2018 International Society for Traumatic Stress Studies.