Symptoms of premenstrual dysphoric disorder (PMDD) respond to serotonin reuptake inhibitors when treatment is limited to 14 days of the menstrual cycle. Many women have less than a week of symptoms, and shorter treatment intervals would further reduce medication exposure and costs.
Twenty women with PMDD were randomly assigned to either paroxetine CR or placebo for 1 cycle and crossed over to the other condition for a second cycle. Subjects initiated treatment when premenstrual symptoms began and stopped within 3 days of beginning menses.
Women took capsules for an average of 9 days (range, 3-15 days), including the first few days of menses. Moderate "PMDD level" symptoms occurred in 1 subject (6%) for 2 days and 4 subjects (24%) for 1 day before starting paroxetine or placebo. Daily Record of Severity of Problems scores were lower in the paroxetine group compared with the placebo group, although the differences were not statistically significant. However, the mean on-treatment Inventory of Depressive Symptomatology (clinician-rated) score for the paroxetine group was 17.9 ± 8.3 compared with 31.5 ± 11.2 in the placebo group (adjusted mean difference = 13.6, P = 0.009). Response (Clinical Global Impressions Scale score of 1 or 2) occurred in 70% of subjects randomized to paroxetine CR and 10% of those assigned to placebo (χ21 = 7.5, P = 0.006). Discontinuation symptoms did not differ in the groups.
These data suggest the need to further evaluate symptom-onset treatment in a larger randomized clinical trial.