Cognitive Improvements Witnessed with THC-CBD Cannabis Extracts and Dementia Patients

A recently published placebo-controlled study from the Journal of Alzheimer’s Disease, explored the effects of sustained use of cannabis plant-derived cannabinoids with dementia patients (1,2). The research found that patients suffering from dementia that has been connected to Alzheimer’s disease (AD) experienced improvements with their cognition.

The research team for the experiment utilized investigators from Brazil and the US. For this study, researchers organized 28 patients that were split into two groups. One group received a placebo or a balanced tetrahydrocannabinol-cannabidiol (THC-CBD) cannabinoid extract (2). The study took place over 26 weeks with cognitive performance of the patients being assessed at baseline, as well as at four, eight, 12 and 26 weeks (1).

Researchers saw that participants in the placebo group showed a reduction in cognitive performance. The group that received the THC-CBD cannabinoid extracted provided different results which showed that participants experienced cognitive improvement. NORML reported that researched expressed that “cannabis’ efficacy as “superior” to those of traditional Alzheimer’s medications,” (1). Additionally, no significant differences were reported from both groups in relation to adverse events.

“In this trial, we report the administration of very low doses of cannabis extract to AD patients … significant[ly] alleviated cognitive loss over a 6-month follow-up period compared to the placebo group,” the study’s authors said (1,2). “Considering AD progression accentuated cognitive decline, we achieved with cannabis treatment remarkable disease stabilization in a half-year period.”

In the author’s conclusion, the researched explained that (2), “To this date, this is the longest clinical trial evaluating cannabinoids effects on AD patients. We initially demonstrate that low-dose THC-CBD potentially can be an effective and safe therapeutic option for AD-related dementia. Nonetheless, larger and longer trials are necessary to confirm this finding and establish cannabinoid administration as therapy for AD dementia.”

According to NORML, this study was the longest clinical trial orchestrated to review how cannabis may be used on patients suffering from AD-related dementia (1).

NORML Deputy Director Paul Armentano said (1), “Because patients using cannabis exhibited changes in their cognitive scores but did not show similar improvements in secondary outcomes, such as sleep quality, it suggests that these cognitive improvements are a direct result of the cannabis intervention rather than an indirect result of other quality of life improvements.”

Healer Webinar Reports on Dementia Research

On June 12th, 2024, Dustin Sulak, DO, founder of Healer, hosted a two-hour webinar on six research studies on cannabis used to treat symptoms associated with Alzheimer’s disease and other dementia related conditions (3). Healer webinars, Dr. Sulak explained, are meant to summarize results and provide commentary on relevant scientific publications on cannabis used for medicinal purposes. He noted that June is Alzheimer’s awareness month and also the theme of this month’s webinar.

The first study examined in the webinar was, “Cannabidiol for behavior symptoms in Alzheimer’s disease (CANbsS-AD): a randomized, double-blind, placebo-controlled trial,” published in International Psychogeriatrics in 2024 (3). One point made in the study was that there are currently no safe and effective approved medications for the behavioral and psychological symptoms of dementia. Dr. Sulak discussed this study’s results and adverse effects, concluding that “this is a preliminary demonstration of safety and tolerability; the acceptability adheres to treatment and signals of potential effect across a range of unmet treatment targets, like apathy, anxiety, agitation and hallucination. So, very promising results. It supports the case for larger studies to evaluate the efficacy of CBD for behavioral symptoms in people with Alzheimer's.”

Another study presented was, “Medical Cannabis for Patients Over Age 50: A Multi-site, Prospective Study of Patterns of Use and Health Outcomes,” which was published in Cannabis in 2024. Dr. Sulak explained the study methods, formulas, changes to pain, mobility, daily activities, and changes to prescription drug use (3). Dr. Sulak commented on the chart comparing drug use at baseline, month three and month six: “It's interesting that cannabis can substitute all of these things and that is likely because it's interfacing with the endocannabinoid system, which is a master regulator of our physiology, and really can do all the things that all these other drugs can do.”

The second half of the webinar was open to questions and comments from attendees. Topics discussed included the effect of cannabis on sleep, updates to the 2024 Farm Bill, cannabis as a Schedule III substance, and uses for other conditions such as neuropathic pain, “chemo” brain,” and diabetes.

References

1. Norml. Cannabis extracts improve cognition in dementia patients https://norml.org/blog/2025/10/31/clinical-trial-daily-use-of-plant-derived-cannabis-extracts-improves-cognition-in-dementia-patients/ (accessed Nov 10, 2025).
2. Cury R de M, da Silva T, Cezar-dos-Santos F, et al. A randomized clinical trial of low-dose cannabis extract in Alzheimer’s disease. Journal of Alzheimer’s Disease. 2025;0(0). doi:10.1177/13872877251389608
3. McEvoy, E. Cannabis and dementia symptoms: Healer Webinar examines relevant research https://www.cannabissciencetech.com/view/cannabis-and-dementia-symptoms-healer-webinar-examines-relevant-research (accessed Nov 10, 2025).