Epidemiology of psychiatric disorders sustained by a U.S. Army brigade combat team during the Iraq War

Objective: This study was designed to describe the epidemiology of psychiatric illnesses experienced by soldiers in a combat environment, which has been previously underreported. Methods: A U.S. Army brigade combat team deployed to Iraq during the Iraq War "Troop Surge" was followed by reviewing unit casualty rosters and electronic medical records for psychiatric diagnoses made by treating providers. The main outcome was the incidence rates of psychiatric disease and nonbattle injury (DNBI). Results: Of the 4122 soldiers deployed, there were 308 psychiatric DNBI casualties (59.8 per 1000 soldier combat-years), which represented 23% of all DNBIs and was second only to musculoskeletal injuries (50% of all DNBI). Most psychiatric DNBI (88%) were treated in theater and returned to duty, 11% were medically evacuated and 1% died. Junior enlisted soldiers, compared with junior officers, and women, compared with men, were at a significantly increased risk for becoming a psychiatric DNBI casualty (77.3 vs. 32.2 per 1000 combat-years, P<.002 and 110.8 vs. 55.4 per 1000 combat-years P<.05, respectively). Conclusions: Psychiatric diagnoses are second only to musculoskeletal injuries as a cause for DNBIs sustained in the current combat environment. Most can be treated in theater and permit soldiers to return to duty.