New Haven, CT – Cannabis use by older adults is
not associated
with either accelerated cognitive decline or greater risk of
dementia, according to
findings
published in the journal BMJ Mental Health.
Investigators affiliated with Yale University and the University of
Oxford in the United Kingdom assessed cognitive performance in
lifetime cannabis consumers and non-users across various domains
— including memory, intelligence, and problem solving. Data
was drawn from two large nationally representative cohorts (the UK
Biobank and the US Million Veteran Program), consisting of several
hundred thousand participants.
Researchers reported that those with a history of cannabis use
“demonstrated significantly better cognitive
performance,” a finding that is
consistent
with prior studies. Cannabis use “was not associated with
increased risk of dementia” and researchers found “no
supporting evidence of a causal link with [longitudinal] cognitive
decline in later life.”
The study’s authors
concluded:
“This study represents one of the largest observational
investigations to date examining the relationship between cannabis
use, cognitive function and dementia risk in older adults. …
Our findings are broadly consistent with prior population-based
longitudinal studies that have not observed accelerated age-related
cognitive decline associated with cannabis use. … Clinicians
can consider that occasional or prior cannabis use may not be a
major contributor to cognitive aging in this population.”
Commenting on the findings, NORML’s Deputy Director Paul
Armentano said: “These results contradict one of the more
prominent and longstanding stereotypes about cannabis and cannabis
consumers. It is unfortunate that these stereotypes often go
unchallenged in the media and elsewhere. It is even more unfortunate
that studies refuting these long-held stereotypes seldom receive the
type of mainstream attention they deserve.”
Several other recent studies have reported similar results. For
example, an Israeli study of over 67,000 older adults
reported
that participants with a history of cannabis use “performed
better across all cognitive domains: attention, executive function,
processing speed, visual and working memory. … Additionally,
past use was associated with a slower decline in executive
function.”
A Danish study similarly
concluded
that cannabis consumers experienced “significantly less
cognitive decline” over their lifetimes than did non-users.
Most recently,
a study
published in January in the Journal of Studies on Alcohol and Drugs
concluded: “Greater lifetime [cannabis] use was also
associated with better performance on cognitive tasks assessing
learning, memory, processing speed, and task switching, aligning
with growing evidence of potential neuroprotective effects of
cannabis in aging populations. … This study adds to a growing
body of evidence that cannabis use may be associated with greater
brain volume and cognitive performance in aging adults, especially
in regions rich in cannabinoid receptors.”
The
full text
of the study, “Cannabis use, cognitive function and dementia
risk in older adults: Observational and genetic analysis,” is
available online. Additional information is available from the NORML
Fact Sheet, “Marijuana Exposure and Cognitive Performance.”
NORML advocates for changes in public policy so that the responsible
possession and use of marijuana by adults is no longer subject to
criminal penalties. NORML further advocates for a regulated
commercial cannabis market so that activities involving the
for-profit production and retail sale of cannabis and cannabis
products are safe, transparent, consumer-friendly, and are subject
to state and/or local licensure. Finally, NORML advocates for
additional changes in legal and regulatory policies so that those
who use marijuana responsibly no longer face either social stigma or
workplace discrimination, and so that those with past criminal
records for marijuana-related violations have the opportunity to
have their records automatically expunged.
Find out more at norml.org and read the NORML Fact Sheets on the
most common misconceptions and myths regarding cannabis and cannabis
policies.
