“These are women who are clinically depressed or anxious for a week or more before menstruation or who have such irritability that emotional symptoms interfere with their ability to function or damage their interpersonal relationships,” said Dr. Susan Girdler, associate professor of psychiatry at the UNC School of Medicine. “We are not talking about most women who have the most common PMS symptoms but the 5 to 10 percent who are really emotionally distraught.”
Volunteers will be paid $500 for several visits to UNC lasting several hours each, Girdler said. They also will receive useful information about their illness, including evaluation with state-of-the-art diagnostic instruments.
Anyone who wants to volunteer can call Astrid at (919) 966-2547 for more information. Researchers, who are especially interested in depression, also are seeking women without PMS but who have had major depression to serve as controls.
Clinicians have known for a long time that female sex hormones are associated in some way with PMS and the more serious premenstrual dysphoric disorder because neither occurs before puberty and both disappear after menopause, Girdler said.
“Paradoxically, women who have PMDD have completely normal ovarian function and show the same hormone levels as other women and the same cycles,” she said. “They are much more sensitive to pain than other women, however.”
Last year, the UNC researchers published a preliminary study in the journal Biological Psychiatry showing that healthy women responded to stress during the second half of their monthly cycles by producing more allopregnanolone, a hormone metabolite of the female hormone progesterone.
Those with the disorder, however, produced less of it during stress.
The new observation could be an important clue as to why some women face such severe symptoms every month, Girdler said. Since taking advantage of the new information might contribute to more effective treatment, she and her colleagues are investigating it further.
“Many women with PMDD are frustrated dealing with the medical community because the disorder is still very misunderstood,” Girdler said. “Many doctors just say, ‘This is normal PMS, just go home, take a break and take some Midol.’ PMDD is much stronger than PMS, however, and we need to help these women if we can.”
Previous researchers have shown that PMDD is not a simple matter of the women having too much estrogen or progesterone, she said. Allopregnanolone strongly affects mood receptors in the brain and is some 200 times more powerful than typical anti-anxiety pills at those receptors.
“It may be that the abnormal stress response of allopregnanolone among women with PMDD contributes to a worsening of symptoms during stress, but that’s speculation because we haven’t measured that directly yet,” Girdler said.
The study published last year involved measuring allopregnanolone levels in women diagnosed as having premenstrual dysphoric disorder and also in others known not to have it, she said. Researchers subjected participants to mildly stressful situations and again measured the hormone levels and symptoms resulting from the artificially induced stress. The new work will focus more intensely on allopregnanolone.
“Among the PMDD women, lower allopregnanolone levels were related to more severe premenstrual anxiety and irritability,” Girdler said. “A similar pattern was seen for depression, but the numbers there were not statistically significant.”
Other faculty members involved in the study are Drs. Leslie Morrow and Kathleen Light, professors of psychiatry. The National Institute of Mental Health supports the UNC study.
Note: Girdler can be reached at (919) 966-2544. Contact: David Williamson, (919) 962-8596
By DAVID WILLIAMSON UNC News Services