Using data from a prospective cohort study of U.S. service members who joined after September 11, 2001 to determine incidence rates and comorbidities of mental and behavioral disorders.
Calculated age and sex adjusted incidence rates of mental and behavioral conditions determined by validated instruments and electronic medical records.
Of 10,671 service members, 3,379 (32%) deployed between baseline and follow-up, of whom 49% reported combat experience. Combat deployers had highest incidence rates of post-traumatic stress disorder (PTSD) (25 cases/1,000 person-years [PY]), panic/anxiety (21/1,000 PY), and any mental disorder (34/1,000 PY). Nondeployers had substantial rates of mental conditions (11, 13, and 18 cases/1,000 PY). Among combat deployers, 12% screened positive for mental disorder, 59% binge drinking, 16% alcohol problem, 19% cigarette smoking, and 20% smokeless tobacco at follow-up. Of those with recent PTSD, 73% concurrently developed >1 incident mental or behavioral conditions. Of those screening positive for PTSD, 11% had electronic medical record diagnosis.
U.S. service members joining during recent conflicts experienced high rates of mental and behavioral disorders. Highest rates were among combat deployers. Most cases were not represented in medical codes, suggesting targeted interventions are needed to address the burden of mental disorders among service members and Veterans.