The expanding population of older women relative to older men or the "feminization of aging" is a significant demographic trend with important implications for the future. Older women are at risk for extended years of widowhood, living alone, institutionalization, poverty, and mental health problems. Although the dementias of late life appear to affect men and women equally, women who develop Alzheimer's disease or related disorders seem more likely to be abused by their caregivers. Women are more likely than men to be primarily responsible for the care of a relative with dementia. Life transitions such as death or illness, and interpersonal losses or conflicts in the caregiving role may be accompanied by depression. The highest incidence of alcoholism in women occurs in widows, and among older women it is the second most common cause for admission into a psychiatric hospital. Women are also likely to be frequent and steady users of psychotropic drugs. The attitudes and biases of mental health professionals are barriers to effective health care for older women, and labor and health care policies have a direct impact on the accessibility and the quality of health care for older women. Society must work to meet the inherent demands of widespread gains in longevity, particularly among women, and to prepare for the changing needs of succeeding age cohorts. This requires an immediate response to ageist and sexist practices detrimental to women and men, both young and old. Research is needed to examine exigencies of the older population and to build sound policy for implementation. Potentially the effects could be far-reaching, influencing future generations. (NRB)