A combination of cannabidiol (CBD) and tetrahydrocannabinol (THC) rapidly and significantly reduces agitation in hospice-eligible people with dementia, according to topline results from the Phase 2 LiBBY clinical trial reported at the Alzheimer's Association International Conference 2026 in London and online on July 28.
Lead investigator Dr. Jacobo Mintzer, psychiatrist at the Ralph H. Johnson VA Healthcare System and professor at the Medical University of South Carolina, said, "This is a robustly positive, randomized, controlled trial that represents a major step forward in treatment for a population that has been historically overlooked in clinical research." Mintzer added, "We now have evidence supporting a new and very effective treatment approach for agitation that may be appropriate for people in the final stages of dementia at the end of life, offering them grace and peace in what is often an extremely difficult time for patients and their families."
The multicenter study was randomized, double-blind, placebo-controlled, and evaluated an oral formulation containing 2 mg THC/100 mg CBD dissolved in digestible oil given twice daily to 120 participants with dementia who were eligible for or receiving hospice care. The trial achieved its primary and key secondary endpoints.
Adverse event rates were similar between groups: 46.7% among those receiving THC/CBD versus 42.4% among those on placebo over twelve weeks. Serious adverse events occurred in 23.3% of participants on active medication compared to 11.9% on placebo; investigators determined none were related to the study drug.
Dr. Jeff Keller, Director of the Institute for Dementia Research and Prevention at Pennington Biomedical Research Center and principal investigator of one study site, said, "People with advanced dementia...have historically been underrepresented in clinical research...The LiBBY study demonstrates that it is possible to conduct rigorous clinical trials with this population...The magnitude and speed of the reduction in agitation we observed with the THC/CBD combination were remarkable." Keller also stated these results address an unmet medical need by offering greater comfort to people with advanced dementia near end-of-life.
Agitation affects about half of people living with dementia near end-of-life; more than one-third continue experiencing symptoms despite off-label use of benzodiazepines, opioids or antipsychotics—therapies associated with significant risks.
The Alzheimer's Association recommends individualized approaches when managing behavioral symptoms like agitation—including nonpharmacological strategies such as environmental modifications—as first-line interventions before considering medications.
