One woman's low is another woman's high: Paradoxical effects of the menstrual cycle.

Although past research on affective changes associated with the menstrual cycle has focussed on a specific pattern commonly referred to as Premenstrual Syndrome, there are compelling reasons to hypothesize that an opposite pattern, with a mid-cycle increase and a premenstrual low in symptoms, may also exist. Focusing on depression and anxiety, the present study tested whether this mid-cycle pattern of symptoms could be identified, using a sample of 213 female university students, who completed daily questionnaires for two menstrual cycles. Results confirmed the existence of a group of women who demonstrate the mid-cycle pattern of symptom changes (13%), in addition to the classic PMS pattern (61%), and individuals demonstrating no cyclical pattern of symptoms (26%). Moreover, women with a strong PMS pattern showed lower average levels of depression/anxiety than women with no cyclical changes. These findings require that current conceptions of menstrual-cycle related psychological changes be redefined to include the mid-cycle pattern, and suggest that women with strong PMS symptoms may actually benefit from a mid-cycle sense of wellness.