Marijuana users have “superior performance across multiple cognitive domains,” according to a new large-scale study funded by the U.S. federal government, with the effects of cannabis on cognition “presented concurrently across a range of brain systems.”
This month, Nature Portfolio published a research preprint that analyzed the brain imaging data and cognitive abilities of 37,929 UK participants aged 44 to 81. The team found that cannabis consumers consistently outperformed non-users on a range of cognitive tests—suggesting that marijuana use may be linked to brain network patterns typically observed in younger individuals.
The paper states that “These results suggest cannabis use could be associated with the deceleration and preservation of cognition in older adults.”
“We speculate that cannabinoids and endocannabinoids may exert neuroprotective effects during aging by preserving an optimal balance between functional segregation and integration—an essential feature for maintaining specialized processing and efficient information transfer across brain networks,” wrote the researchers, who are from the Georgia Institute of Technology, Emory University, Georgia State University, University of Colorado, University of Chinese Academy of Sciences and Tri-Institutional Center for Translational Research in Neuroimaging and Data Science.
Authors of this study supported by National Science Foundation grants and National Institutes of Health grant noted that marijuana laws are evolving and society’s attitudes towards the drug is changing. This has led to a complex view of its effects among older people, in particular.
The authors stated that legalization, greater permissiveness and the recognition of marijuana’s therapeutic potential has contributed to an increase in the consumption of marijuana among the population studied. It was noted that cannabis use among older adults is on the rise, with many using it for chronic health issues.
“Cannabis users exhibited superior performance across multiple cognitive domains.”
Researchers found that cannabis can affect the age-related changes in the brain. However, the researchers warned that marijuana’s effects on older people may be very different than those seen in younger adults.
The research team used advanced neuroimaging methods to fill in gaps of previous research on marijuana’s effect on aging. This included brain scans, cognitive tests, and tens thousands of UK Biobank participants.
Cannabis users showed brain networks with “characteristics associated with younger brains and enhanced cognitive abilities.” This suggests that cannabinoids or endocannabinoids may play a modulatory role in neurodegenerative diseases, potentially supporting resilience. The benefits of cannabis were observed from middle age to late 60s.
They speculated that cannabis use could confer neurocognitive advantages to older adults through modulating functional brain network organization. They speculated that the observed effects indicate cannabinoids exert neuroprotective impacts in aging populations.
This study has the potential of being a major contribution in the area of marijuana research and ageing, but the researchers stressed that further research was needed to understand all the factors at work.
A study from last year showed that cannabis use was associated with a lower risk of subjective cognitive decay (SCD). People who used marijuana for medical or recreational purposes reported less confusion and memory problems compared with non-users.
A separate study in 2023 examining marijuana’s neurocognitive effects found that “prescribed medical cannabis may have minimal acute impact on cognitive function among patients with chronic health conditions.”
While there is still much to be learned about the effects of marijuana on long-term health, recent research suggests that some of these fears are overblown.
A report published in April that drew on dispensary data, for instance, found that cancer patients reported being able to think more clearly when using medical marijuana. It also helped them manage their pain.
A separate study of teens and young adults at risk of developing psychotic disorders found that regular marijuana use over a two-year period did not trigger early onset of psychosis symptoms—contrary to the claims of prohibitionists who argue that cannabis causes mental illness. It was actually associated with modest improvement in cognitive function and reduced usage of other medication.
Yet another study published by the American Medical Association (AMA) last year that looked at data from more than 63 million health insurance beneficiaries determined that there’s “no statistically significant increase” in psychosis-related diagnoses in states that have legalized marijuana compared to those that continue to criminalize cannabis.
Studies from 2018, meanwhile, found that marijuana may actually increase working memory and that cannabis use doesn’t actually change the structure of the brain.