Drinking problems in returning U.S. National Guard soldiers are more likely to be caused by civilian life, rather than wartime experiences, according to new research.

As many as 13 percent of veterans may drink because of problems such as job loss, financial problems or divorce, the researchers found. Almost 7 percent of Americans overall have drinking problems, HealthDay reports.

The study appears in the American Journal of Preventive Medicine.

The researchers collected data on about 1,000 Ohio National Guard soldiers who returned from Iraq or Afghanistan. The soldiers were interviewed three times over three years. They were asked about their alcohol use, as well as exposure to traumatic events such as land mines, vehicle crashes, enemy fire, the deaths of fellow soldiers. They also were asked about their injuries and about stress in their lives since they returned.

Sixty percent of the veterans had experienced combat-related trauma, and 36 percent had experienced problems since they returned. The researchers found 13 percent of veterans reported alcohol abuse or dependence in their first interview, 7 percent in their second interview and 5 percent in their third interview. In addition, 17 percent said they were sexually harassed during their most recent deployment.

Having at least one civilian stressor or an incident of sexual harassment during deployment was associated with an increased risk for alcohol problems in soldiers who had not abused alcohol before, the article notes. The study found combat-related events were only marginally associated with alcohol problems.

“Exposure to the traumatic event itself has an important effect on mental health in the short-term, but what defines long-term mental health problems is having to deal with a lot of daily life difficulties that arise in the aftermath—when soldiers come home,” lead researcher Magdalena Cerdá of the Columbia University Mailman School of Public Health said in a news release.