Despite similar traumatic exposures, peacekeepers and relief workers do not show the same mental health effects as combat veterans, reports a study in the December Journal of Occupational and Environmental Medicine of the American College of Occupational and Environmental Medicine.

Using data from a nationwide mental health survey, the researchers analyzed psychiatric symptoms among 272 U.S. adults who reported working in a war zone as a combat soldier, peacekeeper, and/or relief worker.

Some subjects reported both combat and peacekeeping experience. The lead author was Ellen Connorton of the  Harvard School of Public Health.

Respondents exposed to combat were more likely to be diagnosed with post-traumatic stress disorder (PTSD), with a possible increase in problems with alcohol and drug abuse. There was no evidence of increased mental health problems among people exposed to peacekeeping or relief work only, without combat exposure.

PTSD from combat seems to occur quickly, while most of the effects of combat exposure on drug and alcohol dependence are delayed,” the report said.

They noted that some respondents were diagnosed with depression or other psychiatric disorders were diagnosed before exposure to combat and or peacekeeping/relief work.

Military personnel, peacekeepers, and relief workers are increasingly used to respond to armed conflicts, natural disasters, and other international emergencies.

Some studies have suggested an increased risk of PTSD among peacekeepers, but few studies have looked at the possible mental health impact of relief work.

The new study confirms that combat exposure can have a significant mental health impact. However, in the absence of combat exposure, peacekeeping and relief work were not associated with mental illness.  They believe that future studies should account for previous psychiatric diagnoses and exposure to other types of trauma.