A Cochrane review of four small trials (126 participants) found very low to low certainty evidence that cannabinoids have little or no meaningful effect on cognition or behavioral symptoms in dementia.
Families considering cannabinoids for a loved one with dementia, geriatric clinicians, dementia researchers
Only 126 total participants across all four existing trials
What the researchers found
Across four RCTs testing natural and synthetic THC, there was very low certainty evidence of minimal effect on cognition (1.1-point sMMSE difference) and low certainty evidence of minimal effect on behavioral symptoms (-1.97 NPI difference). Sedation was more common with nabilone.
Why it matters
Despite growing interest in cannabinoids for dementia, this rigorous Cochrane review finds the evidence base is simply too small and too uncertain to draw any meaningful conclusions about benefits or harms.
The numbers in context
4 RCTs; 126 total participants; 3 cross-over designs; 3-14 week interventions; sMMSE difference 1.1 points (very low certainty); NPI difference -1.97 (low certainty); sedation OR 2.83 with nabilone
How the study worked
Cochrane systematic review and meta-analysis of all randomized controlled trials of cannabinoids for dementia treatment, searching multiple databases through July 2021. Four studies (126 participants) met inclusion criteria.
What this study cannot tell us
Only four small studies exist. Short treatment durations (3-14 weeks). Heterogeneous cannabinoid preparations. Most participants had Alzheimer disease, limiting generalizability to other dementias.
How to read the evidence
Cochrane systematic review with GRADE assessment, limited by very small evidence base
When this study was published
Published in 2021. The evidence base for cannabinoids in dementia remains extremely limited.
The bigger picture
The gap between public interest in cannabinoids for dementia and the available evidence is stark. Larger, longer, and better-designed trials are needed before any recommendations can be made.
Questions still open
- Would longer trials show different results? Are specific cannabinoid preparations more promising than others for dementia symptoms? Should future trials focus on specific symptom domains rather than overall dementia measures?
Common questions
Can cannabinoids treat dementia?
Are there risks of cannabinoids for dementia patients?
Read the original research
Cannabinoids for the treatment of dementia.
The Cochrane database of systematic reviews, 9(9), CD012820
Citation
Bosnjak Kuharic, Dina; Markovic, Domagoj; Brkovic, Tonci; Jeric Kegalj, Milka; Rubic, Zana; Vuica Vukasovic, Ana; Jeroncic, Ana; Puljak, Livia. (2021). Cannabinoids for the treatment of dementia.. The Cochrane database of systematic reviews, 9(9), CD012820. https://doi.org/10.1002/14651858.CD012820.pub2
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