July 29, 2026
A combination of THC and CBD, two of the active ingredients in marijuana, reduced agitation in people in the advanced stages of Alzheimer’s disease, according to a new report. Agitation is a common symptom as Alzheimer’s progresses, leading to wandering and aggressive behaviors. Reducing agitation can help ease the burden of Alzheimer’s caregiving and make patients more comfortable.
The study was preliminary and has not yet been peer-reviewed or published in a medical journal. But experts said the trial was rigorous and the results promising and could lead to more effective therapies to treat the agitation of Alzheimer’s. People with Alzheimer’s are often given powerful antipsychotic drugs, sedatives and other medications that have troubling side effects and can shorten lifespan.
“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,” said study author Brigid Reynolds, of Georgetown University Medical Center. “Current treatment options are limited and often carry significant side effects, underscoring the need for safer, more effective therapies.” The findings were presented at the Alzheimer’s Association’s International Conference in London.
For the study, researchers enrolled 120 men and women with advanced Alzheimer’s or other forms of dementia who were exhibiting agitation and related symptoms. Their average age was 80. All were in the advanced stages of Alzheimer’s and eligible for end-of-life hospice care. Some lived at home; others were in nursing homes.
Half were randomly assigned to receive a liquid formula of the medical marijuana compound containing 2 milligrams of tetrahydrocannabinol (THC) and 100 milligrams of cannabidiol (CBD) twice a day. The other half got a lookalike placebo medicine containing no active ingredients. To help guard against bias, neither health care workers nor caregivers knew who was receiving the active treatment.
Caregivers filled out detailed questionnaires about the behavior of those with advanced dementia, noting the severity of a range of symptoms and how often they occurred. They included pacing or wandering, aggressive behaviors like hitting, kicking, spitting or grabbing onto others, or other disruptive behaviors like hoarding or hiding things, eating inappropriate things, asking repetitive questions or making strange noises.
After two weeks, nearly 84 percent of those who were receiving the active medical marijuana formula showed improvements in their agitation scores. By 12 weeks, nearly nine out of 10 showed less agitation. In comparison, less than a quarter of those receiving the placebo formula showed improvements. Side effects were minimal and similar in both groups, and the dose of THC used was low enough that it did not produce a marijuana “high.”
The researchers noted that the 90 percent response rate was impressive and unusual for any clinical trial of a new medication. They were also encouraged that the study showed that those with late-stage dementia, a difficult patient population to study, can be included in clinical trials.
Although the researchers say the results of this trial are encouraging, they caution that the results are preliminary and that follow-up research is needed. They also caution that the treatment evaluated in the trial differs significantly from commercially available THC and CBD products.
“People should not assume that products available at dispensaries or online are equivalent to what was studied in this trial,” Brigid Reynolds said. “The medication used in this research was carefully formulated, manufactured, and administered under close medical supervision. Over-the-counter or commercially available THC and CBD products may vary widely in their composition, quality, and dosing, making them potentially ineffective or even harmful.”
The Food and Drug Administration recently approved a drug called Auvelity to ease the agitation of Alzheimer’s, which appears to be safer than many of the antipsychotic drugs currently used. Nondrug treatments such as music therapy, for example, can also be a safe way to help ease anxiety. Many people with severe Alzheimer’s cannot understand spoken language well, but they can respond to a familiar melody or song from their past. Listening to favorite music can help people with dementia focus and tune out outside stimuli that may be unfamiliar or upsetting. The pleasant feelings and memories elicited by the music can in turn help ease the agitation so common in people with Alzheimer’s disease, making life for caregivers easier as well.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, PhD, of The Fisher Center lab at The Rockefeller University.
Source: Jacobo Mintzer, MD; Brigid Reynolds, MSN: “The Life’s End Benefits of Cannabidiol And Tetrahydrocannabinol (LiBBY) Study Topline Results.” Presented at the Alzheimer’s Association International Conference in London, July 14, 2026
