Combat in Iraq associated with post-deployment PTSD, depression in 8.5 to 14% of soldiers

Between 8.5 percent and 14 percent of soldiers returning from Iraq report serious functional impairment due to either posttraumatic stress disorder or depression, according to a report in the June issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

"A growing body of literature has demonstrated the association of combat in Iraq and Afghanistan with post-deployment mental health problems, particularly posttraumatic stress disorder (PTSD) and depression," the authors write as background information in the article. "However, studies have shown varying prevalence rates of these disorders based on different case definitions and have not assessed functional impairment, alcohol misuse or aggressive behavior as comorbid factors occurring with PTSD and depression."

Between 2004 and 2007, Jeffrey L. Thomas, Ph.D., of the Walter Reed Army Institute of Research, Silver Spring, Md., and colleagues collected anonymous mental health surveys of 18,305 U.S. Army soldiers three and 12 months following deployment. The soldiers were members of four Active Component (non-reserve) and two National Guard (reserve) infantry brigade combat teams. They were screened for PTSD, depression, alcohol misuse and aggressive behaviors, and asked if these problems caused difficulties doing work, taking care of things at home or getting along with other people.

"Using the least stringent definition, we observed PTSD rates across Active Component and National Guard study groups, study time points ranging from 20.7 percent to 30.5 percent, and depression rates ranging from 11.5 percent to 16 percent," the authors write. "Using the strictest definitions with high symptom rates and serious functional impairment, PTSD prevalence ranged from 5.6 percent to 11.3 percent and depression prevalence from 5 percent to 8.5 percent."

Alcohol misuse or aggressive behavior—including slamming a door, punching a wall or threatening or perpetrating physical violence in anger—was present in about half of the cases of PTSD or depression.

Between the three- and 12-month time points, depression and/or PTSD rates remained the same among Active Component soldiers but increased among National Guard soldiers, despite similar rates of combat experiences and similar prevalence rates of mental health problems three months after deployment. "Therefore, the emergence of differences by 12 months likely does not have to do with differences in the health effects of combat but rather with other variables related to readjustment to civilian life or access to health care," the authors write.

The results suggest consequences not only for the care of returning soldiers and their families, but also peers in their units, they conclude. "The findings of the study show that at 12 months following combat, the prevalence of mental health problems among veterans does not abate, and in many cases, increases. It is a virtual certainty that soldiers who remain in service will deploy again; this study shows that a sizable proportion (9 percent to 14 percent) have depression or PTSD symptoms with serious functional impairment," they write. "If soldiers who are struggling with serious functional impairment as the result of a previous deployment are deployed again, there is potential that this could impair their performance in combat. This has implications for the safety of unit members and mission success."