Researchers say former military personnel are twice as likely to commit suicide than people who have not seen combat.
After tracking men who had served in the armed forces over a 12 year period researchers in the United States have found they are twice as likely to die from suicide compared with men in the general population.
Lead researcher Mark Kaplan of Portland State University in Oregon says doctors need to be aware of this and check for signs of suicidal intentions in soldiers returning from service in Afghanistan and Iraq.
The study tracked 320,890 U.S. men over 18 years for 12 years, about a third of whom served in the U.S. military between 1917 and 1994; the others had no military background.
Of the veterans studied, about 29 percent served in the Vietnam War, 28 percent in World War Two, 16 percent in the Korean War and the rest in other conflicts up through the 1991 Gulf War.
The researchers found that those with military service committed suicide at a rate 2.13 times higher than the other men, but did not have a higher risk of dying from disease, accidental causes or murder.
The researchers say the risk was highest in veterans who could not participate fully in home, work or leisure activities because of a health problem.
It was also found that the veterans who killed themselves were also more likely to be older, white, better educated and less likely to have never been married than other suicides.
The study also found that overweight veterans were less likely to have committed suicide than veterans of normal weight and veterans were 58% more likely to use a gun to kill themselves than other suicides.