01/05/2026
A groundbreaking small-scale clinical trial conducted in Brazil has shown promising results in using microdoses of cannabis extract to stabilize cognitive decline in patients with mild Alzheimer's disease. Published in the Journal of Alzheimer's Disease, the randomized, double-blind, placebo-controlled study involved 24 elderly participants aged 60-80.
They received daily oral doses of a balanced THC-CBD cannabis oil containing extremely low amounts—approximately 0.3 mg each of THC and CBD—far below levels that cause psychoactive effects or a "high." Over 24 weeks, patients in the treatment group maintained stable scores on the Mini-Mental State Examination (MMSE), a standard test for cognitive function, while the placebo group experienced noticeable deterioration typical of Alzheimer's progression.
The cannabis group scored about 2-3 points higher on average, representing a modest but clinically meaningful pause in symptom worsening, given that untreated patients often lose 3-4 MMSE points annually. This trial builds on prior preclinical research in mice and a 2022 case report of one patient showing cognitive improvement from similar microdosing over 22 months.
Researchers attribute potential benefits to cannabinoids interacting with the endocannabinoid system, which declines with age and may help reduce neuroinflammation and oxidative stress—key factors in Alzheimer's. As the first human trial testing this microdose approach for Alzheimer's cognitive symptoms, it marks an unprecedented advance amid limited effective treatments.
No significant side effects were reported, highlighting safety at these sub-psychoactive levels. However, the small sample size limits generalizability, and experts emphasize the need for larger, longer multicenter Phase 3 trials to confirm efficacy and explore broader applications for dementia.
