Mood and the menstrual cycle: a review of prospective data studies.

BACKGROUND The human menstrual cycle (MC) has historically been the focus of myth and misinformation, leading to ideas that constrain women's activities. OBJECTIVES We wished to examine one pervasive idea, that the MC is a cause of negative mood, by studying the scientific literature as a whole. We briefly reviewed the history of the idea of premenstrual syndrome and undertook a systematic review of quality studies. METHODS We searched PubMed, PsycINFO, and article bibliographies for published studies using non-help-seeking samples with daily mood data collected prospectively for a minimum of 1 complete MC. We critiqued their methodologies and tabulated the key findings. RESULTS Of 47 English language studies identified, 18 (38.3%) found no association of mood with any MC phase; 18 found an association of negative mood in the premenstrual phase combined with another MC phase; and only 7 (14.9%) found an association of negative mood and the premenstrual phase. Finally, the remaining 4 studies (8.5%) showed an association between negative mood and a non-premenstrual phase. Considering the only 41 adequately powered studies, the same phase links were reported by 36.6%, 41.5%, and 13.5% of studies, respectively. Their diversity of methods (sampling, instruments, and cycle phase definitions) precluded a meta-analysis. CONCLUSIONS Taken together, these studies failed to provide clear evidence in support of the existence of a specific premenstrual negative mood syndrome in the general population. This puzzlingly widespread belief needs challenging, as it perpetuates negative concepts linking female reproduction with negative emotionality.