LiBBY trial results show THC-CBD combo significantly reduces end-of-life dementia agitation

A Phase 2 randomized, double-blind, placebo-controlled trial suggests that a cannabinoid combination of THC and CBD can rapidly and substantially reduce agitation in hospice-eligible people with dementia. The topline results come from the LiBBY (Life’s End Benefits of cannaBidiol and tetrahYdrocannabinol) study and were presented for the first time at the Alzheimer’s Association International Conference 2026 in London and online.

Investigators reported that the oral formulation—2 mg THC/100 mg CBD delivered twice daily—was tested in 120 participants who were eligible for or receiving hospice care and had clinically significant agitation. The study targeted a population often underrepresented in clinical trials: individuals in advanced dementia at the end of life, where effective and safer symptom control is urgently needed.

Lead investigator Dr. Jacobo Mintzer emphasized that the effect was both robust and clinically meaningful. In the trial, participants receiving THC/CBD showed a 6.27-point greater reduction in agitation scores at Week 2 compared with placebo, meeting the primary and key secondary endpoints and indicating rapid onset of benefit.

The improvement persisted through the study’s longer timeframe. By Week 12, the treated group demonstrated an 8.23-point greater reduction in agitation relative to placebo, suggesting sustained symptom relief rather than only short-term effects.

Clinician-rated global improvement supported these findings. At Week 2, 83.9% of participants receiving THC/CBD were rated as improved versus 30.5% on placebo. At Week 12, that increased to 87.2% improved on treatment versus 23.6% on placebo.

Safety signals were assessed alongside efficacy. Overall adverse event rates were similar between groups (46.7% THC/CBD vs. 42.4% placebo), while serious adverse events over 12 weeks occurred in 23.3% of the treatment arm versus 11.9% of placebo. The investigators determined none of the serious adverse events were related to the study medication.

The trial also used a dose-escalation design: participants received a half dose during Weeks 1–1 and then full intervention dosing during Weeks 2–12. This structured approach aimed to balance early tolerability with sustained therapeutic exposure.

Agitation affects roughly half of people with dementia near end of life, and many continue to experience symptoms despite off-label use of medications such as benzodiazepines, opioids, and antipsychotics, which can be difficult to manage and carry risk. The Alzheimer’s Association highlighted the importance of individualized decision-making and shared discussions about prescribing information.

A 12-week open-label extension has been completed and will be reported at AAIC 2026. The LiBBY trial is primarily funded by the National Institute on Aging–backed Alzheimer’s Clinical Trial Consortium, with additional support from the Alzheimer’s Association for the extension, and results are also available via the project website.