(USA TODAY) -- Army women in support units exposed to combat don't have higher post-traumatic stress or depression rates than their male counterparts a few months after leaving Iraq, according to a pilot study due today.

It's believed to be the first research comparing the mental health of men and women in violence-prone support jobs -- medics, mechanics, drivers -- in Iraq, says Army Lt. Col. Carl Castro, chief of military psychiatry at the Walter Reed Army Institute of Research. Castro was scheduled to report his results to the American Psychological Association meeting in Washington, D.C.

"If the argument is women can't handle the stresses of combat as well as men, we see no evidence of a sex difference in these units," Castro says. Women can't serve in front-line combat, "but truck drivers in Iraq have the dangerous jobs," he says, and Army women fill about 10% of such support jobs.

Castro gave mental-disorder screening tests to a random sample of men and women in such posts -- 50 women and 300 men -- three months after their deployment ended. He says there wasn't a statistical difference between the two sexes: About 6% of men and 8% of women had depression, and 11% of men and 12% of women had PTSD symptoms.

"It's possible that sex differences could develop later on," Castro says, "but right now we don't think women need any more mental health help than men."

He had no mental health reports on the soldiers before deployment, so he could not say how combat affected any pre-existing emotional problems.

Not everyone says it's a good idea to put women in positions that could come under fire. "It's not because women don't have 'the right stuff.' Women are very tough mentally," says Janice Crouse of Concerned Women for America, a public policy group that favors traditional family values. "But the best-trained women still can't keep up with the best-trained men physically. If we're putting men in harm's way, we owe them battle colleagues who are just as strong as they are."

Although front-line combat is not permitted for women, "the military has skirted that by putting them in these 'support' roles. It's tantamount to having them in combat," Crouse says.

Says Kim Gandy, president of the National Organization for Women: "There is no job that women should be excluded from because of their gender. If you can do the job, you should have an opportunity to get the job. If you can't, you shouldn't be there, male or female."

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