As more states legalize cannabis, researchers continue to explore whether compounds found in cannabis could help manage the symptoms of Alzheimer’s disease. While “medical marijuana” is often touted as a treatment for various health conditions, its potential for easing dementia’s behavioral symptoms is still a question mark.
As many as half of people living with Alzheimer’s develop agitation — a symptom that can include restlessness, pacing, verbal outbursts, and even aggression. So far, most psychiatric drugs aren’t effective — or necessarily even safe — for people with dementia. The FDA has approved only one drug so far for Alzheimer’s agitation, Rexulti (generic name: brexpiprazole), though it increases patients’ risk of mortality.
Safer alternatives are much needed. But, could cannabis-based drugs — which doctors sometimes prescribe off-label or which caregivers may be able to buy from a dispensary depending on the laws in their home state — actually provide a better alternative, despite that we’re still early in the clinical research for safety and efficacy?
Here’s what clinical trials have revealed about three options currently being studied.
Dronabinol: A purified form of THC
Dronabinol is a lab-made version of tetrahydrocannabinol (THC), the psychoactive compound in cannabis. It’s already FDA-approved to treat nausea and vomiting from chemotherapy and is sold under the brand names Marinol and Syndros.
Could it also help with agitation in Alzheimer’s? Last year, researchers presented new data from a small study that suggests it might. In a three-week trial of 80 people living with Alzheimer’s and agitation, those who took dronabinol showed a slight reduction in symptoms, scoring 0.74 points lower on a 16-point agitation scale compared to those who received a placebo.
The results are promising but far from conclusive. To get a clearer picture, IGC Pharma is running a larger Phase 2 trial with 164 participants. The study is set to wrap up later this year.
Nabilone: A THC-like drug already on the market
Nabilone is another synthetic drug that mimics THC’s effects. It’s FDA-approved under the brand name Cesamet to treat chemotherapy-related nausea and vomiting.
Could it also help calm agitation in Alzheimer’s? One small study of 35 people found that after eight weeks of treatment, nabilone significantly reduced agitation. More recent data presented at an Alzheimer’s conference last year suggests that people with additional symptoms like pain, irritability, or appetite changes — especially those in the earlier stages of the disease — may be the most likely to benefit.
However, researchers haven’t registered any further new clinical trials to confirm its effectiveness.
Cannabidiol (CBD): No clear benefit so far
Unlike THC, cannabidiol (CBD) doesn’t have psychoactive effects, but some research suggests it may help with anxiety. So far, though, there’s little evidence that it works for agitation in Alzheimer’s.
A small double-blind Phase 2 trial tested CBD against a placebo in 15 people living with Alzheimer’s over six weeks. The results? CBD didn’t make a noticeable difference in anxiety or agitation.
That doesn’t mean the book is closed on CBD. Two small, ongoing trials are investigating whether it could help, but it may be years before researchers can say for sure.
The bottom line
Early research suggests that some cannabis-based drugs might help with Alzheimer’s-related agitation. But the evidence isn’t strong enough to draw firm conclusions yet. More clinical trials are needed to determine how safe and effective these treatments really are. For now, experts say caregivers and patients should be cautious. Until more gold-standard research is available, the best approach is still to consult with your doctor — and keep in mind that if something hasn’t been closely studied, it’s tough to know what dosage, formulation, or brand are going to be safe and effective, if any at all.
