WASHINGTON – Deployed troops, and particularly those who’ve been in combat, are at increased risk for sleep problems and associated health risks, according to an Army medical study released Thursday.

More than 70 percent of deployed soldiers have trouble getting more than 6 hours of shut-eye, according to the study, which tracked the sleep habits of more than 3,000 soldiers returning from war. This kind of short sleep duration may increase the risk of post-traumatic stress disorder, depression and substance abuse, as well as more severe traumatic brain injury symptoms, the researchers said.

The findings do not represent a revelation in military circles.

Lt. Col. (Ret.) Dave Grossman, a former West Point psychologist who has written and lectured extensively on the psychological impact of combat, told Stars and Stripes earlier this year that he is convinced that chronic sleep loss is contributing to the rising suicide rate in the military.

Suicide “is a very complex topic,” Grossman said. “But this chronic sleep deprivation is the new factor, a major new factor.”

A Pentagon study into sleeplessness found that the rates of insomnia among Marines and soldiers doubled after a deployment, and the overall rate of clinically diagnosed insomnia, defined as sleeplessness requiring medical intervention at least twice, has increased twentyfold in the past decade.

The study published this week in the medical journal SLEEP recommended servicemembers and their commanders pay special attention to establishing good sleep habits during and after deployments. It called for increased screening as well as clinical services for those found to have a problem.

“Many soldiers returning home from war have difficulty establishing a normal sleep pattern,” one of the authors, Lt. Col. Vincent Mysliwiec, chief of Pulmonary, Critical Care Medicine and Sleep Medicine Service at Madigan Healthcare System, Joint Base Lewis-McChord, Wash., said in a press release. “Short sleep duration is highly prevalent in redeployed soldiers and can negatively impact their lives.”

The roughly three-quarters of soldiers who had experienced combat were far less likely to get sufficient sleep than the others, the study found.