Distribution of positive moods in women with the premenstrual syndrome and in normal women.

ABSTRACT

A daily mood record was kept by 44 women presenting with PMS (PMS+ group 133 menstrual cycles) and by 48 normal women (PMS- group 100 cycles). Peaks of maximum positive mood were located after fitting either a 5-term or a 3-term Fourier series to the data. In the PMS+ group mood peaks were clustered to a significant degree (p < 0.001) around day 11 in a 28-day menstrual cycle (95% confidence interval days 10-12); this is the time of the pre-ovulatory oestrogen surge. In the PMS- group clustering was insignificant. Menstrual cycle parameters were similar in the two groups (PMS+ vs. PMS- mean duration cycle, 27.6 +/- 3.2(SD) vs. 26.7 +/- 2.5 days; incidence ovulatory cycles, 95.5 vs. 93.0%). The evidence suggests either that the ovarian hormone cycle has no effect on mood, or that it has an effect only in women with PMS.