August M
Cannabis has long been associated with teenage experimentation, but new research suggests its impact on the brain may look very different later in life.
Scientists say the findings challenge assumptions that have shaped decades of debate around the drug.
Older users rise
According to UNILAD, cannabis use is increasing sharply among older adults, particularly those who are college-educated, married, female and on higher incomes. The trend was identified by researchers at the Center for Drug Use and HIV/HCV Research (CDUHR) at NYU’s School of Global Public Health.
The findings, published in JAMA Internal Medicine, show a dramatic shift over time. “If we look even further back to 2006 and 2007, less than one percent of older adults used cannabis in the past year. Now, we’re seeing that seven percent have used it in the past month alone,” said Benjamin Han, a CDUHR-affiliated researcher.
Focus shifts to ageing
Most research on cannabis has focused on adolescents and young adults, particularly concerns around developing brains. But as more people age while continuing to use cannabis, researchers are turning their attention to long-term effects later in life.
“More older adults are using cannabis. It’s more widely available and is being used for different reasons than in younger folks — such as for sleep and chronic pain,” said Dr Anika Guha, a clinical psychologist at the University of Colorado Anschutz Medical Campus.
“Plus, people are living longer. We have to ask, ‘What are the long-term effects of cannabis use as we continue to age?’”
Brain scans reveal surprise
Researchers analysed data from 26,362 adults aged between 40 and 77 in the UK. Participants reported their cannabis use, underwent MRI scans to assess brain structure and completed a series of cognitive tests.
The study focused on regions of the brain rich in CB1 cannabinoid receptors, particularly the hippocampus, which plays a key role in memory.
Scientists found that participants who used cannabis performed better on cognitive tests and showed signs of healthier brain structure in some areas.
Experts caught off guard
“I was a little surprised that every cognitive measure that demonstrated a significant effect showed better performance among cannabis users,” Guha said.
“It goes against your default assumptions because I think a lot of research out there has shown cannabis is associated with worse cognitive function, at least acutely.”
Moderation matters
Researchers stress the findings do not mean cannabis is universally beneficial. Guha said moderate users appeared to see the most positive effects, with larger brain volumes and stronger cognitive performance.
She cautioned that responses vary between individuals and said moderation remains key as scientists continue to study how cannabis interacts with the ageing brain.
Sources: UNILAD, JAMA Internal Medicine, NYU School of Global Public Health
