New Study Finds Medical Marijuana Use Does Not Impact Memory or Cognitive Function at Moderate Use

For years, cannabis use has been linked in pop-culture to memory loss and poor focus. But new research published by the American Medical Association challenges that stereotype.

A 2024 study in JAMA Network Open found that adults using medical cannabis for one year showed no measurable decline in working memory, decision-making, or other cognitive

functions [1]. Importantly the findings suggest that light to moderate use may not carry the same cognitive risks often associated with recreational consumption.

So, what exactly did researchers find, and what does this mean for patients who rely on medical cannabis?

Toke hmakes cannabis clear, connecting credible research with trusted, specialist-led care.

 About the study

Researchers from Harvard Medical School, Massachusetts General Hospital, and McLean Hospital conducted a year-long study to understand how medical cannabis use might affect cognitive function over time [1].

The study followed 57 adults who were newly certified for medical cannabis, mostly to manage conditions such as anxiety, depression, pain, and insomnia. Participants underwent functional MRI (fMRI) scans and cognitive tests that measured working memory, attention, and decision-making at the start and after 12 months.

After a year, no statistically significant changes were observed in cognitive performance or brain activation within the medical cannabis group. Comparisons with a healthy control group also showed no activation differences [1].

What researchers found

The study explored how cannabis inluenced three main cognitive areas:

•   Working memory – storing and processing short-term information

•    Reward processing – how the brain responds to positive reinforcement

•    Inhibitory control – regulating attention and decision-making

Across all groups, participants’ cognitive test results and brain scans remained stable after one year [1].

“Working memory, reward, and inhibitory control tasks did not difer statistically from baseline to one year,” the authors reported. “No associations were found between cannabis use frequency and brain activation.” [1]

Participants had light to moderate use patterns (daily users were excluded), and changes in use frequency were not associated with brain activation at one year [1] .

Why these results matter

For decades, the idea that cannabis use inevitably harms memory and focus has shaped public attitudes. But this new evidence shows that context and control matter. For adults using cannabis to help manage symptoms and weren’t consuming heavily daily, the evidence suggests no measurable decline in memory focus, or task-related brainactivity [1].

However, the findings do not address higher doses or heavy/long-term patterns, which require further study [1][2].

Toke helps readers interpret research with clarity and balance, separating scientific findings from assumptions and stigma.

Fast FAQs

Q: Does medical cannabis affect memory or brain function?

No measurable decline was observed. Participants maintained stable working memory, attention, and decision-making scores over 12 months of medical cannabis use [1].

Q: Who participated in the study?

The study followed 57 adults over one year and included a separate healthy control group at baseline [1]

Q: Does this mean medical cannabis is safe for everyone?

Not necessarily. The study focused on adults using cannabis without daily heavy use.

More research is needed on higher doses, younger age groups, and long-term use [1][2].

Q: Are cannabis-based medicines legal in the UK?

Yes. Medical cannabis can be prescribed by GMC-registered specialists for certain

conditions through licensed clinics [3]. CBD products are available over the counter but regulated by the FSA as food supplements [4].

Q: Does medical cannabis improve symptoms like sleep or pain?

This imaging study was not designed to test symptom eficacy [1], guidance on indications and prescribing is available from the NHS and NICE [3][5].

Summary

This study adds to evidence that medical cannabis, when used responsibly, was not associated with impaired cognition over 12 months in this adult cohort [1].

Over the year, participants maintained stable brain function and memory, challenging long- standing assumptions about cannabis and mental clarity. While further research is

essential, these findings provide reassurance for patients who rely on medical cannabis to manage chronic pain, anxiety, and other health conditions.

Toke makes cannabis clear, connecting people to peer-reviewed research, certified products, and clinical expertise for informed, responsible use.

References

[1] Burdinski, D. C. L., Kodibagkar, A., Potter, K., et al. (2024). Year-long cannabis use for medical symptoms and brain activation during cognitive processes. JAMA Network Open, 7(9), e2434354.https://doi.org/10.1001/jamanetworkopen.2024.34354

[2] National Institute on Drug Abuse (NIDA). (2024). Cannabis (Marijuana) Research Report.

https://nida.nih.gov/publications/research-reports/marijuana

[3] NHS. (2024). Medical cannabis (cannabis-based products for medicinal use).

https://www.nhs.uk/conditions/medical-cannabis/

[4] Food Standards Agency (FSA). (2024). Cannabidiol (CBD): Safety and Regulation.

https://www.food.gov.uk/safety-hygiene/cannabidiol-cbd

[5] National Institute for Health and Care Excellence (NICE). (2024). Cannabis-based medicinal products (NG144).https://www.nice.org.uk/guidance/NG144

‍