NEJM 2007;357:820-22 Human beings are living longer, women more so than men. Among people 85 years of age and older, there are 4 men for every 10 women. What happens to sexuality in older age?With increasing age, women were also substantially less likely than men to be involved in an intimate relationship. Among both men and women who were sexually active, approximately half reported at least one bothersome sexual problem. The presence of chronic medical conditions was associated with reduced sexual activity and an increased frequency of sexual problems among both men and women, although it was not a sufficient explanation for the age-related decreases in sexual activity.Most previous studies of the effect of aging on sexuality have involved either men or women, focusing on different factors in each case. Research in men has shown an inverse linear relationship between age and sexuality, even after adjustment for relevant age-related diseases. However, men differ considerably in terms of how quickly they age in this respect. Testosterone acts on the male brain to promote sexual arousal and desire. With increasing age, there are varying degrees of reduction in both free testosterone and the number, and possibly responsiveness, of neurons in relevant areas of the brain such as the locus ceruleus, the brainstem center for testosterone-dependent arousal mechanisms. These changes contribute to the age-related decreases in sexual interest and, to some extent, erectile function. There are age related changes in various aspects of the vascular and smooth-muscle tissues involved in the erectile process, including an increased sensitivity to inhibitory (i.e., contractile) signals in the erectile smooth muscle.

Levels of testosterone in women gradually decrease with age, starting in the mid-30s, independently of menopause. This decrease may contribute to an age-related decrease in sexual interest among some women, as suggested by recent studies evaluating the effect of exogenous testosterone on sexual interest and response. Relationship factors and mental health are likely to be as important as or more important than physiological factors as women age. Whereas many women report a decrease in their sexual interest and responsiveness as they progress through midlife, they are less likely to become distressed or worried about such changes as they get older.