The number of troops with new cases of post-traumatic stress disorder jumped by about 50% in 2007 amid the military buildup in Iraq and increased violence there and in Afghanistan.
Records show that roughly 40,000 troops have been diagnosed with the illness, commonly referred to as PTSD, since 2003. Officials believe that many keep their illness secret.
"I don't think right now we . . . have good numbers," Army Surgeon Gen. Eric Schoomaker said Tuesday.
Defense officials had not previously disclosed the number of PTSD cases from Iraq and Afghanistan.
Army statistics showed that there were nearly 14,000 newly diagnosed cases in all services combined in 2007, compared with more than 9,500 new cases the prior year and 1,632 in 2003.
Schoomaker attributed the rise partly to officials' starting an electronic record-keeping system in 2004 that captures more information, and to the fact that as time goes on, those keeping records become more knowledgeable about the illness. He also blamed more troop exposure to combat.
President Bush's troop buildup increased that exposure, as did the fact that more troops were serving their second, third or fourth tours. Tour lengths were extended to 15 months from 12. And 2007 was the most violent year in both war theaters.