CHAPEL HILL, N.C. -- More than half of women with a very severe form of premenstrual syndrome are likely to have histories of physical or sexual abuse during childhood or adolescence, according to research by scientists at the University of North Carolina at Chapel Hill.
The findings of this study apply to women diagnosed with premenstrual dysphoric disorder (PMDD). This psychiatric condition affects 5 to 10 percent of women in their childbearing years. It is characterized by bouts of major depression and/or anxiety during the second half of the menstrual cycle and severe irritability before subsiding with the onset of each menstrual period.
"About 50 to 60 percent of the PMDD women may have sexual or physical abuse histories. That is much greater than you would expect in the general population,about 20 to 25 percent," says the study's lead author, Dr. Susan S. Girdler, assistant professor of psychiatry at the UNC-CH School of Medicine.
"The severity of PMDD symptoms are as great or can be as great as those of women with full-blown major depression or major anxiety disorder," Girdler adds. "But what makes them different is that the symptoms are very time-limited and linked strongly with the women's menstrual cycle."
Girdler emphasizes that to qualify for PMDD, symptoms must be severe enough to interfere with everyday functioning -- to disrupt relationships, result in social withdrawal, even prompt thoughts of suicide. "We are talking about women who meet very stringent diagnostic criteria for PMDD. This is not the garden variety PMS."
In a report published Nov. 16 in Psychiatry Research, Girdler and her UNC colleagues from the UNC-CH departments of psychiatry and psychology and the School of Public Health note evidence showing that women diagnosed with PMDD also tend to have chronic stress in their lives on a daily basis. This finding, they say, confirms that of other studies and further supports an important role for stress, either as a cause of PMDD or in making its symptoms worse.
The study of 12 PMDD women and 12 healthy women without the disorder looked at responses to life-stress questionnaires, tests of anxiety and depression, and to several stressful experimental situations. These included a "speech stressor" test in which each study subject gave two three-minute talks on what her actions and emotional responses would be to hypothetical interpersonal "hassles." Scenarios included dealings with an inconsiderate houseguest and a used-car dealer. Cardiovascular measures were recorded, as were blood levels of the major stress hormones norepinephrine and cortisol.
In addition to finding evidence of greater chronic life stress and severe traumatic life stress, physiological abnormalities in the stress response system of women with PMDD were documented for the first time.
"We saw evidence that their stress response systems are dysregulated," Girdler says. "Measures of norepinephrine were abnormally elevated in PMDD women, while their cortisol levels were abnormally low. And we saw this regardless what day of the cycle we looked at. This abnormal elevation [in norepinephrine]was found all month long."
As Girdler points out, norepinephrine, a neurotransmitter, is a brain chemical that plays a very important role in regulating mood. "And it has been strongly implicated in depression. So we think that abnormal norepinephrine levels may play a role in premenstrual dysphoria -- depression -- that many of these women experience."
As the UNC-CH team adds more women to the study, differences between the groups persist as stated in the journal report. So far, results confirm other studies that show about 40 percent of women with PMDD have histories of major depressive episodes. "This is separate from PMDD. This is full-blown, long-lasting major depressive episodes," Girdler explains.
To date, Girdler and her colleagues have studied and compared more than 20 PMDD women and their healthy counterparts. They want to enroll more. "These women are often frustrated by their contacts with the medical community. They are very happy to help in any way they can to help validate what they feel is a real physiological disorder," Girdler says. "These women feel very misunderstood. Their disease is very hard to live with, and yet few people understand how disruptive and devastating it can be."
Women interested in volunteering as subjects for the UNC-CH study may contact Sara Benjamin, project coordinator, at 919-966-8029.
Girdler's psychiatry collaborators in the study are senior author Dr. Kathleen C. Light, Dr. Cort A. Pedersen, Dr. Jane Leserman, and Sara Benjamin. Patricia Straneva is from psychology. Catherine L. Stanwyck is from the UNC-CH School of Public Health.
The above story is based on materials provided by University Of North Carolina At Chapel Hill. Note: Materials may be edited for content and length.
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