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

Background: Women are overrepresented in samples of patients with rapid cyc ling bipolar disorder (RCBD), To explore whether menstrually related mood c hanges might account for this gender difference, we studied the relationshi p 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 indi cating their mood and days of menstruation for a minimum of three months, T he data were analyzed for each individual and for the group as a whole, cat egorically (depression, euthymia, and hypomania) and ordinally (0-100, with 0 being "most depressed ever felt" and 100 being "most manic"), with and w ithout normalization of the menstrual cycle to a 28-day cycle. Results: None of the group analyses showed a significant effect of menstrua l cycle on mood. Although some women did exhibit significant relationships between menstrual cycle phase and categorical mood state, there was no cons istent pattern to the relationship. Conclusions: There was no systematic relationship between menstrual cycle a nd mood in a sample of women with RCBD. Biol Psychiatry 1999;46:577-580 (C) 1999 Society of Biological Psychiatry.