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Pentagon data shows that 52 percent of military suicides were committed by active-duty servicemembers who had never been in combat, officials said.
The data was collected from 2008 through 2011, the Los Angeles Times reported Saturday. In 2012, there were more suicides among soldiers who had been deployed for combat than those who had not.
About 20 percent of military suicide victims in 2011 had been diagnosed with a mood disorder such as depression, the Pentagon said, and about half had suffered a failed marriage, often within months of their deaths.
Experts say the higher number of suicides among servicemembers who were never deployed to Afghanistan or Iraq may suggest that mental health issues and life circumstances may play a larger role in military suicide than the stresses of combat.
"A lot of the risk for suicide in the military is the stuff they bring with them," said Dr. Murray Stein, a psychiatrist at UC San Diego who studies suicide in the Army.
Craig Bryan, research director at the University of Utah's National Center for Veterans studies, said the military is more stressful and demanding now than it has been in the past, even for those not sent to war.
"If these servicemembers are coming in with pre-existing vulnerabilities, it's more likely these vulnerabilities will be activated," Bryan said.