Cannabis use among older adults is rising, with approximately 15.4% of Americans older than 12 having used cannabis in the past month, according to 2024 data from the Substance Abuse and Mental Health Services Administration. Older adults—those 60 and older—are the fastest-growing group of cannabis users in the country. According to a 2022 study, adults over 60 who started using cannabis typically did so for medical reasons, including to treat pain, arthritis, sleep disturbances, anxiety, and depression, with more than three-quarters finding it somewhat or very helpful.
However, research reveals complex effects on the aging brain. Cannabis can impair short-term working memory while acutely intoxicated, and consistent users tend to have lasting memory deficits compared with nonusers. A January 2025 study in JAMA Network Open examined over 1,000 adults ages 22 to 36 using brain imaging and found heavy lifetime users exhibited lower brain activity during working memory tasks compared with nonusers. Long-term cannabis use has been associated with changes in brain volume, most pronounced in those who started in adolescence. Yet in adults ages 40 to 70 who began using after roughly age 25, lifetime cannabis use is actually associated with greater brain volume, particularly in areas with cannabinoid receptors.
Available research suggests no overarching association between cannabis use and cognitive decline or dementia risk, though larger and longer studies are needed. Experts emphasize that more research is critical, as federal Schedule I classification limits study opportunities. Research challenges include the need to investigate the effects of different delivery methods and entire cannabis plant compounds rather than isolated cannabinoids.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://us.headtopics.com/news/the-surprising-ways-cannabis-may-affect-the-aging-brain-82375099