LiBBY Trial Results: THC/CBD Reduced Agitation in Late-Stage Dementia
A specific THC/CBD formulation significantly reduced agitation in hospice-eligible people with advanced dementia during a 12-week Phase 2 trial.
Agitation is one of the most difficult symptoms of advanced dementia. It can appear as pacing, repeated vocalizations, restlessness, verbal hostility, or physical aggression. In someone who can no longer communicate clearly, these behaviors may also signal fear, pain, physical discomfort, or another unmet need.
Treatment is especially challenging near the end of life. Environmental changes, structured routines, caregiver support, and other non-drug interventions are generally recommended first. When medication is needed, clinicians may use antipsychotics, benzodiazepines, opioids, or other drugs, but these options do not work for every patient and can cause significant adverse effects.
New findings from the LiBBY trial suggest that a carefully formulated combination of tetrahydrocannabinol (THC) and cannabidiol (CBD) may reduce agitation in people with late-stage dementia who are eligible for hospice care. The results are encouraging, but they require careful interpretation.
Important research note: The findings discussed here were presented at the Alzheimer's Association International Conference in July 2026. The full study has not yet been published in a peer-reviewed journal or indexed in PubMed, and the researchers have not announced when publication is expected. We will update this article as additional data or a peer-reviewed publication becomes available.
What’s the LiBBY trial?
LiBBY stands for the Life's End Benefits of Cannabidiol and Tetrahydrocannabinol Study. It was a National Institute on Aging-funded, multicenter Phase 2 clinical trial designed specifically for people with advanced dementia and clinically significant agitation who were receiving hospice care or were eligible for it.
The study included 120 participants across 10 U.S. sites. Their average age was approximately 80, and most study visits took place in the participants' homes or other places of residence. Participants had Alzheimer's disease or another condition causing dementia.
The study was randomized, double-blind, and placebo-controlled. This means participants were assigned to receive either the active treatment or an inactive oil, and neither participants nor the study teams assessing their symptoms knew which treatment they received during the blinded phase.
The active treatment, called T2, was a purified oral formulation created for the trial. During the first week, participants received 2 mg of THC and 100 mg of CBD twice daily.
From weeks 2 through 12, the dose increased to 4 mg of THC and 200 mg of CBD twice daily, for a total daily dose of 8 mg THC and 400 mg CBD.
This formulation and dosing schedule are important. The trial did not evaluate smoked cannabis, dispensary products, or over-the-counter CBD oils.
Participants rated as behaviorally improved
Clinician-rated improvement in behavior during the LiBBY trial
Week 2
Week 12
Source: LiBBY trial topline results presented at AAIC 2026. The complete study has not yet been published in a peer-reviewed journal.
LiBBY trial at a glance
| Participants | 120 |
|---|---|
| Average age | 80.5 |
| Study sites | 10 U.S. sites |
| Design | Phase 2, randomized, double-blind, and placebo-controlled |
| Population | People with advanced dementia, clinically significant agitation, and hospice eligibility |
| Blinded treatment period | 12 weeks |
| Daily dose after week 1 | 8 mg THC plus 400 mg CBD |
Sources: AAIC 2026 results and ClinicalTrials.gov record NCT05644262.
LiBBY trial results: Did THC/CBD reduce agitation?
In short, yes.
The primary outcome was a change in agitation after two weeks, measured using the Cohen-Mansfield Agitation Inventory. This established clinical scale tracks the frequency of behaviors such as pacing, repetitive movements, shouting, hitting, kicking, or resisting care.
After two weeks, the THC/CBD group had a 6.27-point greater reduction in agitation scores than the placebo group. The difference was statistically significant. The separation between the groups continued through week 12, when the reported difference was 8.23 points.
Clinicians also rated whether participants had improved overall:
At week 2, 83.9% of participants receiving THC/CBD were rated as improved, compared with 30.5% receiving placebo.
At week 12, 87.2% of participants receiving THC/CBD were rated as improved, compared with 23.6% receiving placebo.
These are unusually large differences for a dementia-related behavioral trial. The study also included a 12-week open-label extension in which all participants could receive the active treatment. Researchers reported that participants who switched from placebo began improving and those who continued treatment showed further improvement, although complete extension data have not yet been published.
Did THC and CBD improve dementia or quality of life?
The trial did not test whether THC and CBD could slow dementia, improve memory, restore cognitive function, or change the underlying disease.
Its primary focus was agitation.
Reducing severe agitation may reasonably improve comfort and lessen distress for patients and caregivers, particularly near the end of life. However, the publicly available conference abstract does not report a formal quality-of-life outcome. Headlines saying that the combination was proven to improve quality of life go beyond what the available data directly demonstrate.
A more accurate conclusion is that this specific THC/CBD formulation significantly reduced agitation in hospice-eligible people with advanced dementia during a 12-week Phase 2 trial.
THC/CBD safety and adverse events in the LiBBY trial
Overall adverse events occurred at similar rates in the two groups:
46.7% with THC/CBD
42.4% with placebo
Serious adverse events, however, were more frequent in the THC/CBD group, affecting 23.3% of participants compared with 11.9% in the placebo group.
Detailed conference coverage also reported more serious infections in the treatment group and eight deaths among 61 participants receiving THC/CBD, compared with three deaths among 59 participants receiving placebo.
The investigators reviewed the cases and determined that none of the serious adverse events or deaths were related to the study treatment. Because these participants had advanced illness and were eligible for hospice care, serious medical events and deaths were expected during the study period.
Even so, the imbalance is clinically important. The complete peer-reviewed paper will be needed to evaluate the safety findings, causes of study withdrawal, concurrent medications, and other details more fully. A Phase 2 trial of 120 people cannot establish the long-term safety of a treatment or rule out uncommon risks.
Why the LiBBY trial findings are significant
People with advanced dementia are often excluded from clinical trials. Their medical frailty, limited ability to provide consent, dependence on caregivers, and high likelihood of hospitalization or death can make research difficult. As a result, clinicians have limited high-quality evidence to guide treatment for agitation at the end of life.
LiBBY showed that a randomized, placebo-controlled trial can be conducted in this population, including through visits in patients' homes and residential settings. It also allowed participants to continue other treatments they were already receiving, making the design more representative of real hospice care.
The trial therefore contributes in two ways:
it produced a strong early efficacy signal for a new treatment approach,
and it demonstrated that people with advanced dementia can be included in rigorous clinical research.
What the LiBBY trial does not show
These findings should not be interpreted as evidence that families should give a person with dementia commercially available cannabis or CBD.
The researchers used a purified, precisely dosedformulation manufactured specifically for the study and administered under medical supervision. Commercial products may contain different concentrations of THC, CBD, and other cannabinoids, and their labeling, purity, and consistency can vary. They may also interact with medications commonly used in older adults or increase risks such as sedation, confusion, impaired balance, or falls.
The study also involved a narrowly defined population with advanced, hospice-eligible dementia. Its results cannot automatically be generalized to people with mild or moderate dementia, other behavioral symptoms, or long-term cannabis use.
What happens next for THC/CBD research in dementia?
As of August 7, 2026, there is no announced date for publication of the full LiBBY trial in a peer-reviewed journal. The Medical University of South Carolina reports that the research team is still analyzing participant samples and intends to study the treatment in a larger and broader population.
For now, the findings offer a strong reason for continued research, not a recommendation for unsupervised treatment. If a patient with dementia is experiencing agitation, the first step is a careful medical assessment. Pain, infection, constipation, medication effects, sleep disruption, overstimulation, and other treatable problems can all contribute to behavioral changes. Any consideration of cannabinoids should occur with a clinician who understands the patient's full medical history, current medications, goals of care, and individual risks.
What are IL-7 and IL-15, and how do they differ from inflammation markers like CRP and IL-6 in depression?
Most previous research on depression and the immune system measured CRP, IL-6, and TNF-alpha. Those are smoke alarms. They go off when something is burning: an infection, an injury, an autoimmune flare. The theory was that depression involves a body that is chronically smoldering and that the smoke reaches the brain.
If CRP, IL-6, and TNF-alpha are smoke alarms, IL-7 and IL-15 are the thermostat.
They (are supposed to) keep the immune system's cell populations at the right levels, deciding how many of each type to hold in circulation. When they are off, nothing is burning. The setting is just wrong.
This evolves the question beyond "Is the patient inflamed?" and into "Is the patient's immune system calibrated correctly?"
Curious about cannabis options for chronic pain or other conditions? Contact our office today.
This article is for educational purposes and is not medical advice. Talk with your physician before starting, stopping, or combining any pain treatment.