Substance-use disorders have been declared a national public health emergency.1 Although the rates of substance use are generally lower among older adults than among younger people, this review focuses on older adults.2 Physiological changes in hepatic metabolism that occur with aging affect the pharmacokinetics of both alcohol and other substances, leading to increased susceptibility to harmful effects. Older adults are more likely than younger people to have multiple chronic health conditions and to be using prescription medications that can interact with alcohol and other substances, putting them at increased risk for adverse consequences. To complicate matters, detecting substance-use disorders can be especially challenging in the presence of multiple coexisting medical conditions. Usual social indicators of impaired function, such as difficulty at work, driving errors, or legal charges, may be irrelevant for a person who is retired, is no longer driving, or is consuming substances at home rather than in public. Yet unrecognized substance-use disorders can cause substantial harm to older adults in the form of an increased risk of falls, confusion, cognitive impairment, and medical morbidity, which can contribute to hospitalizations and health care costs, as well as loss of independence.
Large-scale epidemiologic studies conducted over the past 25 years have provided important information about rates of substance use, but longitudinal prospective studies, which would provide data on changing patterns of use, are lacking. In addition, definitions of older age vary among studies, ranging from 45 years of age or older to 65 years of age or older, making it difficult to distinguish differences between middle-aged and older adults. This article addresses the current trends and research related to the prevalence, detection, and management of alcohol-use disorder, prescription-medication misuse, and use of illicit substances among older adults.