Returning soldiers face a number or challenges, and now add to the list a higher risk for alcohol abuse. That's according to a new study from the Journal of the American Medical Association. But some groups are more at risk than others.

As U.S. troops return from war, a new study finds that some may experience serious problems with alcohol.

"We saw an increased risk in newly reported heavy weekly drinking, newly reported binge drinking and newly reported alcohol related problems," said researcher Isabel Jacobson, MPH, Defense Department.

Jacobson and her colleagues analyzed data from more than 48,000 servicemen and women across all branches of the U.S. military, from 2001 through 2006.

"Our findings showed that the individuals who deployed and reported combat exposures were at increased risk for newly reported alcohol behaviors," said Dr. Tyler Smith, MS, Defense Department.

At greatest risk were reserve and National Guard personnel sent into combat. They are 50 percent more likely to begin drinking heavily, defined as having more than 14 drinks per week for men or more than seven drinks per week for women. They were also more likely to start binge drinking, that is, having five or more drinks per day on any occasion.

"We did not see the same findings in those deployed who did not report combat exposures which led us to believe that it was the combat exposures rather than the deployment itself that led to this increased risk in alcohol use," said Jacobson.

Women service members were more likely to experience new heavy weekly drinking compared to men. Younger service members, those born after 1980, were at the highest risk for newly reported binge drinking.

The biggest exception to this was active duty personnel. They did not appear to be at an increased risk for alcohol-related problems even when exposed to combat.