A new study has provided clear insight into contributors to suicide risk among military personnel and veterans who have deployed.

Researchers at the University of Utah found that exposure to killing and death while deployed is connected to suicide risk. Previous studies that looked solely at the relationship between deployment and suicide risk without assessing for exposure to killing and death have shown inconsistent results.

"Many people assume that deployment equals exposure to specific forms of combat trauma, but the two are not equivalent," said Craig Bryan, lead author of the study and director of the National Center for Veterans Studies. "By looking specifically at exposure to death while deployed, it became clear that deployment itself does not increase risk for suicide because not all who are deployed are exposed to death and atrocity."

For the study, researchers analyzed data from 22 studies, totaling 2.7 million participants from multiple eras and across nations, making it the most comprehensive evaluation to be conducted. By reviewing these studies in aggregate, the researchers found much more consistency across data than the individual findings suggested.

Suicide rates have risen among military personnel during the past decade, and it is now the second-leading cause of death. The study found a 43 percent increased suicide risk when people were exposed to killing and atrocity compared to just 25 percent when looking at deployment in general.

"Next, we want to understand why exposure to killing and death leads to an increased suicide risk so we can develop better ways to support military personnel and veterans," Bryan said.

The research team's preliminary results suggest that seeing death and killing contributes to feelings of guilt, shame, regret and negative self-perceptions. Other research Bryan has conducted indicates that self-forgiveness protects against suicide attempts, and he plans to pursue this topic further so veterans and military personnel will have better support in dealing with trauma and transitioning to civilian life.

The findings are detailed in the journal Suicide and Life-Threatening Behavior.