Alcohol abuse by elderly persons may be overlooked by clinicians because the effects of alcoholism on intellectual processes may be attributed to advancing age. In older patients, in whom liver and other organ functions may be reduced, even modest social drinking will impair cognitive abilities. Alcoholism is especially detrimental to older persons because 1) their blood levels of ethanol are higher than those in younger persons, and brain neurons may be more sensitive to the drug; 2) ethanol can disturb their sleep and sexual performance; 3) their cognitive functions may be significantly impaired by ethanol; and 4) for elderly patients, who commonly take a variety of drugs, ethanol and drug interactions are particularly hazardous.