The number of suicides among active duty U.S. troops has risen dramatically over the first five months of 2012 compared to the same period in years past, averaging just under one each day, according to an analysis by the Associated Press.

In the first 155 days of the year, there were 154 military suicides, the highest total in 10 years. That total represents an 18 percent increase over last year, when the military saw 130 suicides over the same period, and it's a 25 percent increase from 2010.

Those totals include only troops who were currently serving, and not veterans who had returned to their private lives.

The number of self-inflicted fatalities  in 2012 also tops the total number of servicemen and women who've been killed in combat in Afghanistan this year by about 50 percent, according to data also obtained by the Associated Press.

The cause of the spike in suicides is not known, though studies have suggested a link between post-traumatic stress and multiple tours of duty to an increased likelihood of suicidal thoughts. Faced with mounting suicide totals and questions about the mental health of its soldiers, the Department of Defense has sought to promote more robust couneling and prevention programs for troops.

"A key component of our commitment to maintaining this trust [in our troops] is our ongoing effort to reduce the stigma of seeking help when needed," Brig. Gen. Barrye L. Price, a Defense Department spokesman, wrote in a press release announcing April's suicide total. "By achieving a cultural change that encourages help-seeking behaviors, we will be postured to more effectively combat suicide within our ranks."