March 3, 2000 (Atlanta) -- Women with a severe form of premenstrual syndrome are more sensitive to pain and are more likely to have chronically lower levels of beta-endorphins, the body's natural painkilling hormones, according to a new study. Called premenstrual dysphoric disorder (PMDD), it affects millions of women in their reproductive years.
For women with PMDD, emotional symptoms like severe depression, irritability, and anxiety profoundly interfere with their lives during the second half of the menstrual cycle. "These women also suffer from many severe physical symptoms -- migraine, headache, backache, bloating, cramping," lead author Susan S. Girdler, PhD, tells WebMD. Girdler is assistant professor of psychiatry at the School of Medicine at the University of North Carolina at Chapel Hill.
"It's a very severe disorder, yet it's not taken seriously by doctors," Girdler says. "The vast majority of PMDD women coming into my clinic to some extent want to be validated. When I first began this research, I was shocked. Some women have full-blown panic attacks, are afraid to leave their houses, have suicidal thoughts. It continues to be a very misunderstood disorder, yet it's a very important issue for women."
Results of Girdler's small study, which focused just on pain sensitivity, were presented at the American Psychosomatic Society annual meeting this week. While a preliminary study had suggested that women with PMDD have increased pain sensitivity three to seven days before menstruation, Girdler's study showed that the sensitivity extended into all phases of the PMDD woman's cycle.
Hers is the first study to measure blood levels of beta-endorphins while testing pain sensitivity. It supports a growing body of research suggesting that PMDD is a chronic disorder that causes abnormal levels of many hormones, including beta-endorphins, at all times of the month. "It suggests that something happens premenstrually, that elevated sex hormones during that week contribute to symptom expression," says Girdler.
Girdler's study used a tourniquet/blood pressure cuff, which has been proven effective in gauging pain sensitivity, she says. The women were tested during two phases: the premenstrual phase, and the week after menstruation began.
The study involved 54 women, including 27 with PMDD and 27 who did not have it. The average age was 35. During the 20-minute test, pressure was gradually increased until the woman expressed pain, then it was continued until the woman could no longer tolerate it. Before the cuff was deflated, women were asked to rate how unpleasant and how intense the pain was.
"We found that the PMDD women were significantly more sensitive to the pain test," Girdler tells WebMD. "They had significantly lower threshold levels and tolerance times. They couldn't endure the test nearly as long as the control group, regardless [of] what phase they were in [in] their menstrual cycle. They also rated the test procedure as being significantly more unpleasant."
Moreover, the women's beta-endorphin levels also were significantly lower during both cycles at rest and during pain testing, says Girdler.
Her results support a long-standing theory that hormones in the body called endogenous opioids -- specifically, beta-endorphins -- may contribute to this disorder, because endogenous opioids not only regulate physical symptoms but influence mood as well, says Girdler.
Thus far, treatment of PMDD has been limited; most women are advised to make behavioral and dietary changes. "Folklore suggests that exercise helps, and indeed beta-endorphins are released during exercise. Unfortunately, the controlled studies of this disorder looking at exercise, diet, and herbal supplements have not been done, or have been done so poorly that we can't say definitively what works," says Girdler.
Some evidence suggests an association between histories of major clinical depression and women who develop PMDD, says Girdler. Large-scale clinical trials investigating antidepressants are being sponsored by the National Institutes of Health. Selective serotonin reuptake inhibitors (SSRIs) show the most promise in treating emotional symptoms of this disorder, says Girdler. (For more information on these trials, women can visit the NIH's new web site, http://clinicaltrials.gov/ .)
Valerie Ratts, MD, assistant professor of reproductive endocrinology at Washington University in St. Louis, has researched PMDD and tells WebMD, "I think it's very important if we can understand some of the reasons why people have PMDD. We need better treatments for it. Right now, we don't have much."
Simple measures can be tried first. Ratts advises women to get regular aerobic exercise, avoid foods containing refined sugars and caffeine (including sodas and chocolate), follow a well-balanced diet, and take a daily multivitamin. When they are having a bad day, women should try to reschedule important meetings for another time if possible, to inject a bit of laughter, and to give themselves small personal rewards. "Anything to make them feel better," she says.
- A researcher says that women who suffer from a severe form of premenstrual syndrome called premenstrual dysphoric disorder, or PMDD, are more sensitive to pain and have lower levels of the body's pain-fighting chemicals compared to women the same age who do not have PMDD.
- Women with PMDD suffer both emotional symptoms like severe depression, anxiety, and irritability and physical ones like migraines, backache, bloating, and cramping.
- Doctors are still trying to find the best ways to treat PMDD. One doctor recommends regular aerobic activity and a good diet that eliminates refined sugar and caffeine. Women also should provide themselves with mental boosts.