A new study published this month suggests that the duration of treatment for a severe form of premenstrual syndrome called premenstrual dysphoric disorder (PMDD) is important for determining whether a person will relapse or not. The researchers also found that symptom severity at the onset of treatment is a good predictor of relapse.

According to the researchers, approximately half of the patients who demonstrated improvement experienced relapse within 6 to 8 months after discontinuing treatment with the antidepressant drug, sertraline (Zoloft).

Overall, longer treatment was marginally better in preventing relapse.

But both the rate of relapse and time to relapse were highly associated with symptom severity at baseline. Patients with severe symptoms at baseline were significantly more likely to experience relapse after discontinuing the drug. These patients also experienced relapse after a shorter period, and were significantly more likely to experience relapse during extended drug treatment compared with patients in the lower symptom severity group.

Patients with lower symptom severity at baseline were less likely to experience relapse regardless of treatment duration, and the time to relapse was significantly longer.

According to the researchers, premenstrual syndrome (PMS) continues to be one of the most common health problems reported by women of reproductive age. The morbidity of PMS is due to the severity of the symptoms, the resulting impairment of work, personal relationships, and activities, and its chronic nature over many years of menstrual cycling.

Treatment of the severe form of PMS, termed premenstrual dysphoric disorder (PMDD), with serotonergic reuptake inhibitors (SSRIs) has consistently demonstrated efficacy, and the U.S. Food and Drug Administration has approved the use of sertraline hydrochloride, fluoxetine hydrochloride, and paroxetine hydrochloride for this indication.

“There is little information about the optimal duration of treatment,” noted the researchers, although anecdotal reports and small pilot investigations suggest that premenstrual symptoms return rapidly in the absence of effective medication.”

The study was conducted on 174 women with PMS or PMDD and was led by Ellen W. Freeman at the University of Pennsylvania School of Medicine, Philadelphia.

The women were randomly divided in two groups. Eighty-seven of them received short-term treatment by taking sertraline (Zoloft) for four months and then switching to placebo for fourteen months. The second group of eighty seven participants received long-term treatment of sertraline (Zoloft) for twelve months and placebo for six months. Neither the women nor the researchers had knowledge of the treatment assignments.

Following treatment, results showed that 72 percent presented improvement during the first four months.

After short-term treatment, 60 percent of women showed deterioration with an average midpoint time of four months.

After long-term treatment, 41 percent of women experienced relapse with an average midpoint time of eight months.

“Patients with severe symptoms at baseline were more likely to experience relapse compared with patients in the lower symptom severity group and were more likely to experience relapse with short-term treatment.”

“How long medication should be continued after achieving a satisfactory response and the risk of relapse after discontinuing treatment are important concerns for women and clinicians,” noted the researchers, “given the possible adverse effects and cost of drugs vs. the benefit of medication that improves symptoms, functioning and quality of life.”

“These findings suggest that the severity of symptoms at baseline and symptom remission with treatment should be considered in determining the duration of treatment.”

The study appears in the May issue of the Archives of General Psychiatry (one of the JAMA/Archives journals).

Source: Archives of General Psychiatry