(Medical Xpress) -- Women who served in the U.S. Army in Iraq and Afghanistan were involved in combat at significantly higher rates than in previous conflicts, and screened positive for post-traumatic stress disorder at the same rate as men, according to a study led by researchers at the San Francisco VA Medical Center and the University of California, San Francisco.

“While women technically are not supposed to serve in direct combat, this research demonstrates that, in reality, they are experiencing combat at a higher rate than we had assumed,” said lead author Shira Maguen, PhD, a clinical psychologist at SFVAMC and an assistant clinical professor of psychiatry at UCSF. “At the same time, it shows that men and women really don’t differ in how they react to the stresses of combat.”

Women in the U.S. military gradually have been integrated into combat roles since the early 1990s, and today comprise about 14 percent of Americans serving in uniform. Of roughly 2.2 million troops who have served in and Afghanistan, more than 255,000 have been women, according to the Pentagon. Under current U.S Army rules, women are not officially assigned to units whose primary mission is direct combat on the ground, but can be assigned to other roles in combat zones.

The study of 7,251 active-duty soldiers who served in Iraq and Afghanistan is the first study, the authors say, to include gender as a variable in examining responses to four combat-associated traumatic experiences: killing, witnessing someone being killed, exposure to death (seeing dead soldiers or civilians) and injury.

The authors found that 4 percent of women reported killing, 9 percent reported witnessing killing, 31 percent reported exposure to death and 7 percent were injured in the war zone.

In contrast, according to one study of the 1990-91 Gulf War, 1 percent of women reported killing, 14 percent reported witnessing someone dying and 2 percent suffered a combat-related injury. (Gulf War statistics on exposure to killing and death are not parallel with Iraq and statistics because the questions were asked differently in the earlier study.)  

The authors of the current study, published electronically in the Journal of Psychiatric Research on Dec. 14, 2001, found that for most categories of combat stress, the mental health effects on men and women were the same, with men and women screening positive for PTSD at the same rate – 18 percent. There was one statistically significant exception: women injured in combat were more likely to screen positive for PTSD than injured men.

Men overall were somewhat more likely to report post-deployment problem drinking, and women overall were somewhat more likely to report depression symptoms.

Twelve percent of women reported exposure to military sexual trauma (MST), defined as sexual assault or repeated sexual harassment, as opposed to 1 percent of men – a figure consistent with other research on combat-zone MST, noted Maguen. “However, there was no gender difference in the response to MST,” she said. “Whether you were a man or a woman, MST was strongly associated with PTSD and depression.”

Maguen said the study has important implications for the VA health care system. “If women are indeed being exposed to combat stressors at a higher rate than in prior eras, we have to be prepared to provide the services they need, and take into account the impact that these stressors can have on their mental health functioning,” she said. “We also need to take a closer look at physical injury and its potential impact on ’s psychological health.”

Co-authors of the study are David D. Luxton, PhD and Nancy A. Skopp, PhD of the Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury, Tacoma, WA., and Erin Madden, MPH, of SFVAMC.

The study was supported by funds from the Department of Veterans Affairs.

SFVAMC has the largest medical research program in the national VA system, with more than 200 research scientists, all of whom are faculty members at UCSF.

UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.