The largest study to date of a rising suicide rate among military personnel, published Wednesday in JAMA Psychiatry, found no connection between suicide and deployment overseas in support of the wars in Iraq and Afghanistan.

The findings are the latest in a series of studies prompted by a military suicide rate that has nearly doubled since 2005. The study’s authors and others cautioned, however, that the findings do not rule out combat exposure as a reason for the increase in suicides, adding that more information was needed.

“As the wars went on, the suicide rates also went up and it was very tempting to assume deployments must be the reason,” said the lead author, Mark Reger of the Department of Defense National Center for Telehealth and Technology in Tacoma, Wash. “Our data don’t support that. But there may be important subgroups, including those exposed to combat, that we need to look at further.”

The suicide rate for troops deployed in support of the fighting in Iraq and Afghanistan, the study found, was only slightly higher than for troops who did not deploy to that area or remained stateside — 18.86 deaths versus 17.78 deaths per 100,000. The national average is about 13 deaths per 100,000.