• Agitation and aggression: Limited. T wo placebo-controlled trials of prescription THC capsules showed calmer behavior over 3 to 6 weeks. The larger , published in 2026, gave 75 patients 5 mg of dronabinol twice daily for 3 weeks: agitation fell on one of two main measures, with a trend on the other (Rosenberg 2026).
• Memory and disease progression: Not established. No human study shows cannabis protects memory.

Compared with standard treatment: Antipsychotics used for agitation carry a warning for increased risk of death in dementia. The dronabinol trial was well tolerated, without delirium or seizures, but lasted only 3 weeks; a larger 140-patient trial of oral dronabinol began in 2026.

Good to know: Older adults are sensitive to THC. Start very low with a caregiver watching for dizziness, confusion, and f alls.

What to ask for: Low-dose THC by mouth (capsule or tincture), the type used in the agitation trials, ideally prescription dronabinol or nabilone. Avoid high- THC and inhaled products. Have a caregiver manage doses.