Premenstrual syndrome (PMS) and especially its severe form, premenstrual dysphoric disorder (PMDD), have been afflicting women for eons (Psychiatric News, May 16, 2008).
So when the SSRI antidepressants were found to be effective for PMS and PMDD, and when the Food and Drug Administration approved several SSRIs for these ailments, many women had reason to celebrate.
But how long women must stay on an SSRI to keep PMS or PMDD at bay depends on whether they have PMS or PMDD, a new study has found.
The lead investigator of the randomized, double-blind, placebo-controlled study was Ellen Freeman, Ph.D., director of the PMS research program in the University of Pennsylvania's Department of Obstetrics and Gynecology. Results were published in the May Archives of General Psychiatry.
The study cohort consisted of 174 women with either PMS or PMDD. Half received the SSRI sertraline for four months, the other half received sertraline for an entire year. In all cases, 50 mg of sertraline a day was given only to the women following ovulation during the luteal phase of the menstrual period—the standard SSRI treatment for PMS or PMDD.
All subjects were then placed on a placebo and followed up for six months. The researchers compared outcomes for the two groups of subjects.
During the six-month follow-up period, 51 percent of the short-term treatment group relapsed, whereas only 33 percent of the long-term treatment group did. But when baseline severity of symptoms was considered, those subjects with PMDD relapsed two-thirds of the time, whereas those with PMS relapsed only a third of the time regardless of how long they had been treated.
So, “overall, women are less likely to relapse after stopping SSRIs if treated for 12 months compared to four months,” Freeman told Psychiatric News. “[But] severity of the symptoms is an important consideration. Women with severe symptoms are likely to relapse after stopping SSRIs regardless of the duration of medication.”
Freeman and her colleagues likewise found that just as subjects with PMDD were especially prone to relapse, so were those subjects with a history of depression (about half the sample). So are women who have PMDD the same women who are also subject to depression? “No,” Freeman said.“ There is likely overlap between the disorders, but PMDD is not depression.”
Suppose a patient has both PMDD and a history of depression. What SSRI regimen would most benefit her? “Carefully monitor her to determine the symptoms and severity over the entire menstrual cycle—not just premenstrual—and carefully evaluate her response to the dosing regimen,” Freeman advised. “If premenstrual dosing does not sufficiently control symptoms, then daily dosing, possibly with an increase in the premenstrual phase, should be tried.”
Still, “no definitive studies” have been conducted to date to determine whether PMDD per se is better countered by taking an SSRI during the entire menstrual cycle, not just during the luteal phase, Freeman noted.
The study was funded by the National Institute of Child Health and Human Development.
