A federally funded clinical trial found that combining THC and CBD produced a significant, lasting reduction in agitation among nearly all participants living with Alzheimer's disease or other forms of dementia.
The double-blind, placebo-controlled study tested a cannabis formulation called T2:C100, containing 2mg THC and 100mg CBD, in 120 dementia patients who qualified for hospice care and were experiencing notable agitation.
Researchers from the Medical University of South Carolina and Georgetown University recorded a statistically significant improvement on a standardized agitation scale for patients receiving the cannabis treatment versus placebo, measured both two weeks in and at the 12-week close of the study.
By week two, 84 percent of patients on THC/CBD improved according to caregiver ratings, compared with 31 percent on placebo. By the trial's end, 87 percent of those receiving the medication—made by MediPharm Labs—showed improvement, versus 24 percent in the placebo group.
Findings were presented this month at the Alzheimer's Association International Conference. The study abstract states the THC/CBD combination "may be an important therapeutic tool" for agitation tied to Alzheimer's and related dementias.
Lead investigator Jacobo Mintzer said in a press release: “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. 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 trial, known as LIBBY (Life's End Benefits of cannaBidiol and tetrahYdrocannabinol), enrolled patients with an average age of 80.5 and was funded by the National Institutes of Health and the Alzheimer's Association.
Elizabeth Edgerly, the Alzheimer's Association's vice president for care and support, said the trial "directly addresses one of the most challenging and under-discussed aspects of Alzheimer's disease—end-of-life agitation."
Co-principal investigator Brigid Reynolds said: “Agitation affects many people with late-stage dementia, causing symptoms such as restlessness, aggression and emotional distress that can profoundly impact patients and their caregivers. Current treatment options are limited and often carry significant side effects, underscoring the need for safer, more effective therapies.”
Separately, the American Medical Association last month adopted a resolution recognizing both the risks and potential therapeutic benefits of marijuana use by older adults, noting a higher dementia incidence among cannabis users while also citing potential benefit for managing agitation as an alternative to antipsychotic medications.
A study published last year found CBD showed "promising" results in reducing inflammation and cognitive decline tied to aging. A 2024 review concluded that THC, CBD and lesser-known phytocannabinoids, terpenes and flavonoids in marijuana are "promising agents in treating neurodegenerative disorders."
