More U.S. soldiers killed themselves in July than were killed by the enemy in Afghanistan as the Army's monthly suicide rate for active duty troops more than doubled to a record high of 26.

Another 12 potential suicides occurred among Army Reserve and National Guard soldiers who were not on active duty. The total of 38 suicides in July surpassed the total of 32 soldiers killed in Afghanistan last month, the Army reported Thursday.

The suicide tally rose from 12 active-duty soldiers in June to 26 in July, while the numbers remained the same for the Reserves and National Guard – 12 in June and July.

The increases baffled and frustrated Gen. Lloyd J. Austin III, the Army's vice chief staff, just as they did his predecessor, Gen. Peter Chiarelli, who struggled to erase the stigma in the military that sometimes attaches to soldiers who seek help for emotional problems.

"Suicide is the toughest enemy I have faced in my 37 years in the Army," Austin, the former commander of U.S. troops in Iraq, said in a statement.

"And it's an enemy that's killing not just soldiers, but tens of thousands of Americans every year. That said, I do believe suicide is preventable," Austin said. "To combat it effectively will require sophisticated solutions aimed at helping individuals to build resiliency and strengthen their life coping skills."

The other services also faced increased rates of suicide and the same daunting task of finding methods of prevention.

Read Jacey Eckhart's column on the military suicide contagion.

The Marine Corps, which has begun stressing suicide prevention and awareness in basic training, reported eight suicides in July to bring the total for the year to 32 – equal to the number for all of 2011.

Air Force incidents of suicide for active duty, Guard and Reserves through July totaled 63, already five more than in 2011. The Navy had 39 suicides through the first seven months of this year, compared to 52 in 2011.

Since 2008, the Defense Department put more than $110 million into its Military Suicide Prevention Program, setting up suicide hotlines, hiring mental health professionals and conducting wide-ranging studies of suicide risk.

The services have also ordered up mandatory mental health screenings and emotional resilience training, and cracked down on bullying and hazing in the ranks, but the funding and the programs have yet to curb the suicide rate or discover a pattern that might let therapists devise treatments. Troops who have never deployed are as likely to commit suicide as those with multiple combat assignments.

For the first seven months of the year, the services reported a total of 321 suicides for active-duty, Guard and Reserve forces. In Afghanistan, 231 U.S. troops had been killed this year with the combined total for U.S. and coalition forces at 297.

"Something's wrong," Defense Secretary Leon Panetta told the annual suicide prevention conference in June of the Departments of Defense and Veterans Affairs.

Panetta called suicide in the military "perhaps the most frustrating challenge" he has faced since becoming secretary last year.

"There are no easy answers, but that is no damn reason for not finding the answer to the problem of suicide," Panetta said.