The US Army said Thursday 115 soldiers on active duty committed suicide in 2007, the most in one year since the service began keeping records in 1980. Nearly a thousand soldiers attempted suicide.
The spike came in a year that saw the highest US casualties in Iraq and increased levels of violence in Afghanistan, but officials said the trend has continued into 2008.
Barack Obama, the front-runner for the Democratic presidential nomination, called it "a tragic reminder of the staggering and ongoing costs of the Iraq war, particularly on our troops and their families."
Army officials acknowledged that long and repeated combat deployments were a major source of stress in soldiers' lives, but they found no direct relationship between increased conflict and suicides.
"In terms of this current conflict we see a lot of things going on in the war which do contribute," said Colonel Elspeth Ritchie.
"Mainly it is the long time and multiple deployments away from home, the exposure to really terrifying and horrifying things, the easy availability of loaded weapons, and, of course, it's very, very busy right now," she said.
In a report, the army said the 115 confirmed suicides raised the suicide rate to 18.8 percent per thousand for the active duty army in 2007, or 16.6 percent if based on a larger pool that includes reservists on active duty.
The suicide rate among active service members was 17.3 per 100,000 in 2006, compared to 12.8 in 2005 and 10.8 in 2004. In 2001 the rate was 9.8 per 100,000.
The suicide rate for the US population, adjusted for the age group and gender, is 19.5 percent.
"It's the highest number since the army has been keeping records," Colonel Thomas Languirand said of the suicides in 2007.
So far this year there have been 38 confirmed suicides and 12 suspected cases, he said, adding that that was comparable to last year.
There were 935 suicide attempts by soldiers in 2007, including 166 during deployments to Iraq or Afghanistan, according to the report.
Forty-three percent of those who killed themselves did so after being deployed; 31 percent took their lives during deployments; and 26 percent were soldiers who had never deployed, according to the report.
"Suicide behaviors were significantly more common for young, Caucasian, unmarried, junior enlisted soldiers," the report said.
"Younger, lower-enlisted female soldiers were overrepresented for suicide attempts compared to completions," it said.
Most of those who committed suicide in Iraq or Afghanistan were on their first tour.
About half of the soldiers who completed suicide had a recent failed intimate relationship, the report said.
Officials said only six percent had been previously diagnosed with post traumatic stress disorder, but officials said most of those who killed themselves had not previously sought medical help.
"In the army what we have more often is a sudden loss, a humiliation, a breakup, or trouble at work, and an immediate precipitating event, and unfortunately all too often, immediate action," Ritchie said.
"And again one of the most potent risk factor is the access to loaded weapons," she said.