Low-Dose THC-CBD Extract Showed Cognitive Benefit in 26-Week Alzheimer's Trial
In the longest clinical trial of cannabinoids in Alzheimer's patients to date, a very low dose THC-CBD extract led to significantly higher cognitive scores compared to placebo over 26 weeks.
Quick Facts
What This Study Found
Patients receiving low-dose THC-CBD extract (0.350 mg THC + 0.245 mg CBD daily) had significantly higher Mini-Mental State Exam scores at week 26 compared to placebo.
Key Numbers
Daily dose: 0.350 mg THC + 0.245 mg CBD. Duration: 26 weeks. Significant improvement in MMSE total score vs placebo.
How They Did This
Phase 2, randomized, double-blind, placebo-controlled trial. Participants aged 60-80 with Alzheimer's dementia received either placebo or THC-CBD extract orally for 26 weeks.
Why This Research Matters
Alzheimer's has very few effective treatments. A 26-week trial showing cognitive benefit with a remarkably low cannabinoid dose could open a new treatment avenue.
The Bigger Picture
This is the first long-duration RCT to show a cognitive signal with cannabinoids in Alzheimer's.
What This Study Doesn't Tell Us
Phase 2 trial, likely small sample. Only the primary outcome was significant. Requires replication.
Questions This Raises
- ?What is the mechanism at such a low dose?
- ?Can results be replicated in a larger Phase 3 trial?
Trust & Context
- Key Stat:
- 26-week RCT: low-dose THC-CBD significantly improved cognitive scores vs placebo
- Evidence Grade:
- Randomized, double-blind, placebo-controlled Phase 2 trial; moderate because it needs replication.
- Study Age:
- 2025 publication of a 26-week trial
- Original Title:
- A randomized clinical trial of low-dose cannabis extract in Alzheimer's disease.
- Published In:
- Journal of Alzheimer's disease : JAD, 108(4), 1602-1613 (2025)
- Authors:
- Cury, Rafael de Morais, da Silva, Taynara, Cezar-Dos-Santos, Fernando(2), Fakih, Yasmin Rafaela Correia, Narvaez, Karlin Andrea Ramírez, Gouvea, Murilo Chaves, Espínola, Carlos, Ferreira, Charles Francisco, de Castro, Wagner Antonio Chiba, Pamplona, Fabrício Alano, Silva, Elton Gomes da, Bicca, Maíra Assunção, Nascimento, Francisney Pinto
- Database ID:
- RTHC-06280
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
How low was the dose used?
Extremely low: 0.350 mg of THC and 0.245 mg of CBD per day. A typical recreational dose might contain 5-10 mg of THC.
Does this mean cannabis can treat Alzheimer's?
It is too early to say. This is a single Phase 2 trial. Larger and longer trials are necessary.
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Cite This Study
https://rethinkthc.com/research/RTHC-06280APA
Cury, Rafael de Morais; da Silva, Taynara; Cezar-Dos-Santos, Fernando; Fakih, Yasmin Rafaela Correia; Narvaez, Karlin Andrea Ramírez; Gouvea, Murilo Chaves; Espínola, Carlos; Ferreira, Charles Francisco; de Castro, Wagner Antonio Chiba; Pamplona, Fabrício Alano; Silva, Elton Gomes da; Bicca, Maíra Assunção; Nascimento, Francisney Pinto. (2025). A randomized clinical trial of low-dose cannabis extract in Alzheimer's disease.. Journal of Alzheimer's disease : JAD, 108(4), 1602-1613. https://doi.org/10.1177/13872877251389608
MLA
Cury, Rafael de Morais, et al. "A randomized clinical trial of low-dose cannabis extract in Alzheimer's disease.." Journal of Alzheimer's disease : JAD, 2025. https://doi.org/10.1177/13872877251389608
RethinkTHC
RethinkTHC Research Database. "A randomized clinical trial of low-dose cannabis extract in ..." RTHC-06280. Retrieved from https://rethinkthc.com/research/cury-2025-a-randomized-clinical-trial
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.