Summary: A randomized, placebo-controlled clinical trial shows a specially formulated oral THC/CBD medical oil produced rapid, substantial reductions in end-of-life agitation among people with late-stage dementia. The Phase 2 LiBBY trial followed 120 hospice-eligible participants and found a 6.27-point greater decrease in Cohen‑Mansfield Agitation Inventory (CMAI) scores in the active treatment arm versus placebo within two weeks. Nearly 90% of patients receiving the active formulation experienced sustained behavioral improvement over 12 weeks, and adverse events were similar between groups—suggesting a potentially effective, better-tolerated alternative to traditional heavy sedatives for severe dementia-related agitation.
Key Facts:
- High response rate: 87.2% of participants treated with the study’s medical THC/CBD formulation had clinically meaningful behavioral improvement by 12 weeks, an unusually large response in dementia pharmacotherapy trials.
- Fast onset of effect: The rapid-acting oral oil suspension produced a 6.27-point greater reduction in mean CMAI agitation scores compared with placebo at the two-week primary endpoint.
- Focused on hospice-eligible patients: The LiBBY trial enrolled 120 hospice-eligible adults with Alzheimer’s disease or other dementias (mean age approximately 80) across 10 U.S. centers; all study visits were performed in participants’ homes to minimize stress from travel.
- Strict medical formulation and oversight: Investigators emphasized that the trial medication is a purified, precisely dosed pharmaceutical preparation of delta-9‑THC and CBD and cautioned this cannot be replicated with unregulated retail or dispensary cannabis products.
Source: Georgetown University Medical Center
Overview of the trial and main findings
In what investigators describe as a first-of-its-kind study, U.S. researchers tested a carefully formulated oral suspension combining tetrahydrocannabinol (THC) and cannabidiol (CBD) against placebo to treat severe agitation in people with late-stage dementia. The LiBBY trial (Life’s end Benefits of cannaBidiol and tetrahYdrocannabinol) was designed to measure effectiveness, safety, and tolerability of a rapid-acting medical oil suspension delivered under close clinical supervision.
The study enrolled 120 hospice-eligible patients with Alzheimer’s disease or other dementias, conducting home-based visits across 10 medical centers. Participants were randomized to receive either the active THC/CBD combination or a matched placebo. Treatment assignments were blinded to participants, caregivers, and clinicians to preserve objectivity. The average participant age was about 80 years.
Agitation was measured with the 29-item Cohen‑Mansfield Agitation Inventory (CMAI), a caregiver-rated instrument that scores frequency of agitated behaviors on a seven-point scale from “never” to “several times per hour.” The trial set a primary outcome at two weeks because the oil suspension was formulated to act quickly—important for patients nearing the end of life. At two weeks, the active-treatment group showed a 6.27-point greater reduction in mean CMAI scores versus placebo; this benefit was maintained at 12 weeks.
A secondary outcome, the Clinical Global Impression of Change in Behavior, echoed the CMAI results: at two weeks, 83.9% of the THC/CBD group were rated as much less agitated versus 30.5% in the placebo group; at 12 weeks, corresponding figures were 87.2% versus 23.6%.
Overall adverse event rates were similar between groups (46.7% active vs. 42.4% placebo) and largely reflected conditions common in this frail patient population, including infections and gastrointestinal complaints. Investigators reported no unexpected safety signals attributable to the study medication.
Clinical and caregiver implications
Agitation in late-stage dementia—manifesting as restlessness, aggression, repetitive behaviors, or emotional distress—places a heavy burden on families and professional caregivers. Current pharmacologic options, such as antipsychotics, benzodiazepines, and opioids, offer limited benefit and often cause sedation, loss of awareness, or other harmful side effects. In contrast, the investigational THC/CBD oil in LiBBY reduced agitation without entirely suppressing awareness, enabling moments of connection and improved patient comfort in many cases.
Family members who participated in the trial reported meaningful changes. One participant’s daughter described renewed moments of happiness and connection during visits, even though she did not know whether her mother had received active medication or placebo.
Key Questions Answered:
A: The LiBBY medication is a pharmaceutical-grade, purified suspension with precisely controlled ratios and doses of delta-9‑THC and CBD formulated to act rapidly when taken orally. Retail and online CBD/THC products are unregulated and may vary widely in purity, potency, and dosing; they are not equivalent to the clinical formulation used in this trial and could be ineffective or unsafe for frail, late-stage patients.
A: Because participants were hospice-eligible and often near the end of life, researchers prioritized a fast-acting treatment to provide prompt symptom relief. The oil suspension was engineered for rapid digestion and onset, so the two-week timepoint was chosen to detect emergency relief, while the 12‑week assessment evaluated durability of effect.
A: Severe agitation is commonly described as one of the most distressing and exhausting symptoms for caregivers. Treatments that lower agitation while preserving patient awareness can restore moments of connection, dignity, and calm for both patients and families, reducing reliance on heavy sedatives that can render patients unresponsive.
Funding and acknowledgements
The investigators expressed gratitude to LiBBY study participants, caregivers, and families for their time and commitment. The trial was supported by a National Institutes of Health cooperative agreement (grant #R01AG068324-01) and the Alzheimer’s Association. The study is conducted by the NIH-funded Alzheimer’s Clinical Trial Consortium and coordinated by the University of Southern California’s Epstein Family Alzheimer’s Therapeutic Research Institute, the Medical University of South Carolina, and Georgetown University. ClinicalTrials.gov identifier: NCT05644262.
Editorial notes
- This article was edited by a Neuroscience News editor.
- The journal paper was reviewed in full by the editorial team.
- Additional context was added by staff knowledgeable in dementia research.
About this dementia research news
Author: Karen Teber
Source: Georgetown University Medical Center
Contact: Karen Teber – Georgetown University Medical Center
Image: Image credited to Neuroscience News
Original research presentation: Main findings presented at the Alzheimer’s Association International Conference in London.