Menstrual factors in sleep.

The changing endocrine profile in premenopausal women alters aspects of sleep and circadian rhythms. Subjectively women appear to feel a greater need for sleep and report poor and insufficient sleep more often than men. This greater sleep requirement may manifest with a higher amplitude of slow-wave sleep in the EEG in women. Healthy young women, with biphasic body temperature rhythms of ovulatory menstrual cycles, have more stage 2 sleep, higher spindle frequency activity and less rapid-eye movement (REM) sleep when progesterone predominates in the luteal phase. These sleep-EEG changes may largely be caused by neurosteroids acting on the brain. Sleep regulatory mechanisms, indicated by the onset to sleep, slow-wave sleep (SWS) and slow-wave activity, appear to be unaffected by menstrual phase in women with normal cycles. Women with premenstrual mood symptoms have more stage 2 sleep and seemingly less SWS and REM sleep, a blunted circadian rhythm of melatonin and an earlier minimum body temperature than asymptomatic women. Subjective repercussions include increased daytime sleepiness, lethargy and fatigue. Treatment strategies for menstrual-associated complaints include using oral contraceptives and sleep deprivation but the physiology and pharmacology of normal menstrual changes, the disorders and their treatment need to be better understood.