Substance Use in Older AdultsSubstance Use in Older Adults By 2050, 85. 7 million people in the United States are projected to be 65 or older. Older adults are especially prone to the effects of substances, and a 2021 survey showed that 4 million older adults were dealing with a substance use disorder. As the country's population ages, clinicians will inevitably have to care for a greater number of older adults with substance use disorders, but the literature on the topicand the