Sex Differences in Sleep

Abstract

There are sex differences in sleep behavior with women reporting more sleep problems and a poorer sleep quality than men across a wide age range. The poorer self-reported sleep quality in women appears to relate in part to their increased likelihood to experience depression and anxiety symptoms and in part to social factors such as socioeconomic status. In contrast to the self-report findings, polysomnographic recordings show that women have better sleep than men across a wide age range, suggesting that objective and subjective assessments are tapping into different constructs of sleep. Women have less nonrapid eye movement (N1 sleep), fewer awakenings, and more slow-wave sleep (N3 sleep) and slow-wave activity (SWA, ∼0.4–4.5 Hz) within the sleep electroencephalograph than men. The higher level of SWA in women is apparent from young adulthood through old age. Further sex differences in sleep become apparent under challenging conditions, with women showing a more pronounced response to sleep deprivation and a different pattern of sleep disturbances in association with major depressive disorder compared with men. Sexual differentiation of sleep may be instigated in part through the organizational and activational effects of sex steroids. There are also sex differences in the prevalence of diagnosed sleep disorders, with women being more likely to have insomnia and men more likely to have obstructive sleep apnea. Sex, therefore, is an important factor in determining sleep behavior, sleep architecture, and sleep disorder prevalence and presentation.

Keywords

• Adolescence
• Estrogen
• Insomnia
• Menopause
• Menstrual cycle
• Obstructive sleep apnea
• Sleep quality
• Slow-wave activity