Lack of relationship between menstrual cycle phase and mood in a sample of women with rapid cycling bipolar disorder

Background: Women are overrepresented in samples of patients with rapid cycling bipolar disorder (RCBD). To explore whether menstrually related mood changes might account for this gender difference, we studied the relationship between menstrual cycle phase and mood in a sample of premenopausal women with rapid cycling bipolar disorder (RCBD). Methods: Twenty-five women with RCBD completed daily self-rating forms indicating their mood and days of menstruation for a minimum of three months. The data were analyzed for each individual and for the group as a whole, categorically (depression, euthymia, and hypomania) and ordinally (0–100, with 0 being “most depressed ever felt” and 100 being “most manic”), with and without normalization of the menstrual cycle to a 28-day cycle. Results: None of the group analyses showed a significant effect of menstrual cycle on mood. Although some women did exhibit significant relationships between menstrual cycle phase and categorical mood state, there was no consistent pattern to the relationship. Conclusions: There was no systematic relationship between menstrual cycle and mood in a sample of women with RCBD.