Post-traumatic stress disorder has been a recognized condition in combat veterans since 1983. Women make up 17 percent of the U.S. armed forces, and since 2001, 280,000 women in the military have been deployed for tours of duty in Iraq and in Afghanistan. Of those, 150 were killed in action and 800 were wounded.

Yet there is a paucity of knowledge about PTSD in female combat veterans.

Deane Aikins, Ph.D., associate professor of Psychiatry and Behavioral Neurosciences, is working to change that with an ongoing study of PTSD in female veterans in Michigan. He is using a combination of reliving a stressful scenario with an extremely limited use of beta blockers to train the body to reduce the physical reaction to traumatic memories.

"With PTSD, we don't have one similar reaction in all veterans," Dr. Aikins said. "During those times of stress, the heart rate can triple within 60 seconds of thinking about trauma. But not everyone has flashbacks. Everyone is different in their reaction to PTSD and how they react to it. In those receiving the placebo, we see the heart rate shoot up. In those we've tested using the beta blocker, their physiological response can be as neutral as a walk through Walmart."

The goal is not to erase or even minimize the traumatic memory, but to teach the body to develop a different reaction to the stress associated with it. "Our hypothesis is that with this method you are weakening and uncoupling the memory association between the event and the hyper-arousal that comes with PTSD," Dr. Aikins said. "In effect, the patient's body learns to not be physically upset by the memory."

Veterans in the study agree to participate in four sessions. Each receives a medical screening and writes a description of two memories, one about a pleasant or neutral event, and the second a memory of a traumatic event related to military service that still causes stress. They write descriptive paragraphs of both memories, and Dr. Aikins records a 30-second narrative of both events.

In subsequent sessions, Dr. Aikins attaches to the veterans sensors for heart rate, frown muscles and sweat monitors on fingers. Veterans listen to the pleasant or neutral tape for one minute on headphones. They are asked to keep that image in mind and then are given a placebo or a beta blocker while their vital signs are monitored for two hours. If the subject's vital signs appear good, they receive a second pill and then are sent home with 100 milligrams of the drug or a placebo. Seventy-two hours later, the subject returns to the office to listen to the recording of the traumatic incident. They again are given the drug or placebo and vitals are monitored.

Veterans return a month - and a menstrual cycle -- later to listen to the trauma memory recording again and have a final diagnostic interview.

Researchers, Dr. Aikins explained, found the beta blocker had a better impact on females in an animal model. "We think it will work better with women. Hormones may facilitate the treatment. Women could be more adept at coping with stress. We just don't know yet. We have some statistical detail, but it doesn't translate to clinical practice yet. That's why we're conducting the study."

To date, he said, subjects receiving the placebo appear to experience no change in their reaction to stressful memories a month later. In the group receiving the beta blocker, however, after a month their physiology does not react to the trauma as it would before treatment.

Beta blockers are often used to treat hypertension and to regulate heart rate. They also have been used by people stressed about public speaking and by athletes. They have been prescribed for PTSD as a long-term therapeutic, but that use has not been very effective, Dr. Aikins said.

"We are not looking to use the beta blocker as a long-term crutch as a coping mechanism," he said. "We have them face the fear, then take the pill. Taking the beta blocker just this one time might be enough to undo the physical reaction to the traumatic experience."

The stress of combat is something many civilians cannot comprehend, Dr. Aikins said. "Our service members have seen women and children used as bombs and may have had to kill those people. They have seen terrible things. These are horrible things for all of us to be confronted with. We ask them to make hard calls and do sometimes terrible things." In addition, the stress for female veterans can also be rooted in Military Sexual Trauma as sexual assault while serving in the military.

Women in combat as members of the armed services is a relatively new phenomenon for the United States, Dr. Aikins said, with the wars in Iraq and Afghanistan. Women have been in combat areas in previous military engagements, but mainly as nurses and support personnel. "We've known about combat stress, what we now call PTSD, for at least 60 years," he said. "PTSD was officially recognized in 1983, 10 years after the end of the Vietnam War. Before the wars in Iraq and Afghanistan, our scientific knowledge of combat stress physiology came from studies that included a combined total of only 700 veterans, and only 33 of those were women. There is a huge gap in military and clinical literature on combat stress on women and the female stress response."

Female veterans are under-represented in PTSD treatment studies, Dr. Aikins said. "It's difficult to get veterans of Iraq and Afghanistan to participate. Some feel seeking help is a stigma. Some female veterans who are victims of a sexual assault in the military may not want to relive the experience, or feel help is not available because the assault was not handled correctly by their commanders or their commanders may have been the perpetrators. It may be a sense of not knowing where to seek treatment. We do everything we can to help these warriors."

The study, which seeks only female veterans, pays subjects $400 for their participation. Women must be younger than 45. For more information about the study, call 313-437-3953.