A CBD, THC Combination Reduced Dementia Agitation in Nearly 9 in 10 Patients

For the millions of families who have watched a loved one with late-stage dementia suffer through agitation, restlessness and distress in their final months, new research presented at the Alzheimer’s Association International Conference 2026 in London offers something that has been painfully scarce in this space: a promising, evidence-based answer.

A Phase 2 clinical trial called LiBBY, short for Life’s End Benefits of Cannabidiol and Tetrahydrocannabinol, has found that a combination of CBD and THC significantly and rapidly reduced agitation in people with advanced dementia who were eligible for or receiving hospice care. The results were described by the investigative team as a major step forward for a population that has been historically overlooked in clinical research.

What Is Agitation in Dementia and Why Does It Matter?

Agitation affects approximately half of people living with dementia near the end of life, and it is one of the most distressing symptoms for patients, families and caregivers alike. Because individuals in the late stages of dementia often lose the ability to communicate effectively, agitation frequently serves as a behavioral signal of physical discomfort, fear or unmet needs. Symptoms can include pacing, repetitive movements, loud vocal outbursts, verbal hostility and physical behaviors like hitting or scratching.

More than one-third of dementia patients continue to experience agitation despite treatment with existing options, including benzodiazepines, opioids and antipsychotics, all of which carry significant risks and can be difficult to manage in a hospice setting.

What Did the Study Find?

The LiBBY trial enrolled 120 participants with Alzheimer’s disease or another dementia-causing condition who were experiencing clinically significant agitation. Participants received either a novel oral formulation combining 2 milligrams THC and 100 milligrams CBD twice daily or a placebo across a 12-week period.

The results were striking. By Week 2, participants receiving the THC and CBD combination showed a 6.27-point greater reduction in agitation scores compared with those on placebo, demonstrating rapid symptom relief. By Week 12, that gap had grown to 8.23 points.

Looking at clinician-rated global improvement, 83.9% of treated participants showed improvement at Week 2 compared with just 30.5% on placebo. By Week 12, 87.2% of treated participants had improved versus only 23.6% of those on placebo.

Nearly nine in 10 participants who received the treatment showed overall improvement by the end of the study.

“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,” said lead investigator Jacobo Mintzer, M.D., psychiatrist at the Ralph H. Johnson VA Healthcare System and professor at the College of Health Professions, Medical University of South Carolina, Charleston.

Was It Safe?

Overall side effect rates were similar between the treatment and placebo groups. Serious side effects occurred in 23.3% of participants in the treatment group compared with 11.9% in the placebo group over 12 weeks, but investigators determined that none of the serious effects were related to the study medication itself. The study population was notably diverse, with a mean age of about 80 years, 55% female and 58% from historically underrepresented ethnoracial groups.

What Does This Mean for Patients and Families?

This is a Phase 2 trial, meaning the treatment is not yet approved and further research is needed. However, the findings represent meaningful progress for a population that has had very few effective, safe options. For families caring for a loved one with advanced dementia, these results offer a reason for cautious hope that more humane and dignified end-of-life care may be on the horizon.

“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,” Mintzer concluded.