A study examining more than 67,000 older adults has found that cannabis use was not universally harmful to cognitive function and was even associated with better performance in some areas, according to research published in the journal Age and Ageing.
The research, which analysed data from the UK Biobank of participants aged 60 and older, revealed that 17% reported using cannabis at least once in their lifetime, with 4% having used it within the past year. Lifetime users performed better across all cognitive domains – including attention, executive function, processing speed, visual memory and working memory – compared to those who had never used cannabis.
“Past use was linked to better performance and slower decline in some cognitive domains,” the researchers explained. “However, specific usage patterns, such as longer duration, were associated with poorer outcomes in other domains. These findings highlight the need for further research to clarify underlying mechanisms and guide evidence-based recommendations regarding cannabis use in aging populations.”
The study, led by researchers Sharon Sznitman, Shira Vered and Gabriel Weinstein, included both cross-sectional analysis of 67,713 participants and longitudinal analysis of 52,002 participants with an average age of 67 years.
Current cannabis users – defined as those who had used within the past year – demonstrated particularly strong working memory performance. The research also found that past cannabis use was linked with slower decline in executive function over time.
However, the results were not uniformly positive. Early onset of cannabis use, along with duration and frequency, showed associations with improved attention and visual memory, but former users who began consuming cannabis before age 17 demonstrated poorer working memory compared with those who started later.
The researchers acknowledged several limitations, including potential recall bias from self-reported data and the inability to distinguish between medical and recreational cannabis use. The study also lacked information on dosage, specific cannabinoids consumed and methods of administration.
The findings add weight to previous research showing a positive link between cannabis and cognitive ageing. A systematic review of 18 studies published earlier this year in the Journal of Cannabis Research found that whilst long-term cannabis use starting early in life might negatively affect cognitive function and brain health in older adults, cannabis use initiated during later life could improve quality of life and support healthy ageing, particularly when prescribed as cannabis-based medicinal products.
