Timing and severity of symptoms associated with the menstrual cycle in a community-based sample in the Midwestern United States.

This study describes the experience of menstruation among normal women, establishing a baseline for comparison with women reporting symptoms of a menstrual disorder. A community-based sample of 900 women kept a daily log of 50 physical, social, and psychological symptoms for a period of time that included two menstrual cycles. Twenty-five items were derived from the DSM-IV criteria for premenstrual dysphoric disorder (PMDD) and 13 from the premenstrual syndrome (PMS) literature. An additional 12 items were positively worded versions of some of the PMDD items. Women were told that the study was about women's health, with no specific reference to menstruation. Time sequence charts revealed that all symptoms peaked on the first day of menses, with severity levels more than 2 S.D. above the mean for each individual symptom. Women were more likely to endorse distress when symptoms were positively worded than when they were negatively worded. This study shows the importance of reducing bias in self-reports of menstrual symptoms, and illustrates the lag between hormonal changes in the luteal phase and the peak of symptom severity at onset of menses. Further research is needed to determine the nature and extent to which women with a presumed disorder vary from this baseline pattern.