Psychologists are leading a five-year effort to discover the best treatments for combat-related post-traumatic stress disorder (PTSD) as part of a grant described as the largest ever awarded by the Department of Defense to study the issue.

Slated to start by year's end, the estimated $25 million effort--called the STRONG STAR Multidisciplinary Research Consortium--will include eight randomized clinical trials. Researchers will recruit participants on active duty and people who have recently left the military who have been diagnosed with PTSD, says Alan Peterson, PhD, of the University of Texas Health Sciences Center at San Antonio.

"The DoD has never put this amount of money to this before," Peterson says.

Funded by the DoD's Peer Reviewed Medical Research Program, the consortium is also unique for drawing military, Department of Veterans Affairs and civilian researchers, he says.

Psychologists estimate that about one in six service members who have deployed to Iraq or Afghanistan experience PTSD symptoms. That estimate rises to one in three among service members wounded in action, and is also thought to be higher for National Guard and Reserve service members.

Risk for PTSD is also estimated to be higher for service members who have deployed to Iraq or Afghanistan more than once, Peterson says. So far, about 1.6 million service members have deployed to Iraq or Afghanistan.

"Based on the number of individuals who have deployed, it's in the hundreds of thousands of people that are at risk for PTSD," he says.

The consortium includes some of the top researchers in the PTSD treatment field, including Patricia Resick, PhD, developer of Cognitive Processing Therapy (CPT) and Edna Foa, PhD, the developer of Prolonged Exposure Therapy. Resick will oversee a trial treating service members diagnosed with PTSD in three study groups: CPT delivered in a group-therapy format, CPT delivered to individuals, and a control condition in which participants work through problem-solving skills as part of a group.

Foa will oversee a trial treating service members diagnosed with PTSD in two study groups: Prolonged Exposure Therapy delivered in 10 treatment sessions over eight weeks or 10 sessions delivered over two weeks.

Both Resick and Foa will assess the success of the treatments by measuring the participants' functioning in their professional and personal lives, as well as the reduction of the severity of PTSD symptoms. The trials are scheduled to take place over the next five years, and the insights gained about treatment will be disseminated as soon as possible, Peterson says.

Resick says the comparison of group and individual CPT made possible by the grant has important public policy implications. "Group therapy is more cost effective, so if group and individual treatments are equivalent, then group therapy is justifiable. However, if individual therapy is more effective, then agencies and institutions, such as the VA and DoD, will have to plan accordingly," Resick says.

If PTSD can be successfully treated in therapy intensively delivered over two weeks, researchers think treatment would be much more accessible for veterans in rural areas, who could take a break from work or school, get treated and return home, Foa says.

Researchers want to learn which PTSD treatments work best because early intervention allows active-duty service members to continue to serve and enables discharged veterans to return to school or work, Peterson says.

"If we don't figure out the best way to be treating individuals, we could have an entire generation of combat veterans that are in a similar situation as Vietnam veterans," he says. "It's critically important for us to figure this out."