• Posted July 15, 2026

THC/CBD Combo Might Ease Agitation In Late-Stage Dementia

Agitation is a common and tough-to-control symptom of late-stage dementia. But a new trial suggests that a combination of two active ingredients in marijuana may help ease patients' agitation.

The specially formulated medication contains purified tetrahydrocannabinol (THC) and cannabidiol (CBD), given by mouth in an oil that's rapidly digested.

Most patients (90%) responded favorably to the medication, achieving significant reductions in their agitation levels based on standardized scales, researchers said.

“These trial results were extremely impressive and showed a level of response not seen before in clinical trials related to dementia," said study co-leader Dr. Jacobo Mintzer, a professor at the Medical University of South Carolina in Charleston. "Rarely do we see close to 90% of patients in a trial respond positively to a new medication."

Researchers presented the findings Tuesday at the Alzheimer’s Association International Conference in London. 

"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 co-lead Brigid Reynolds. "Current treatment options are limited and often carry significant side effects, underscoring the need for safer, more effective therapies." 

Reynolds is an adult care nurse practitioner at the Georgetown University Memory Disorders Program in Washington, D.C.

Her team noted that drugs such as Valium and Haldol can be somewhat effective, but come with their own side effects. 

Could a combo of THC and CBD work better?

To find out, the new trial enrolled 120 people in the late stages of Alzheimer's or other forms of dementia. Patients averaged 80 years of age and received either the THC/CBD combo therapy or a placebo over a period of 12 weeks.

Because the drug is thought to be relatively fast-acting, changes in agitation were first tested at the two-week mark. Researchers used a standard "29-factor agitation assessment survey" that rated patient agitation levels on a 7-point scale ranging from “never” to “several times per hour."

By the end of week two, people taking the THC/CBD combo drug experienced an average 6.27-point reduction in their scores compared to patients taking the placebo, the researchers reported. The benefit seemed to be sustained over the full 12 weeks of the study.

Another analysis, using a different measurement of agitation levels, showed similar results. 

The drug appeared safe, with no differences seen in terms of gastrointestinal disorders or infections, the team noted.

Importantly, the study was double blinded — neither the physicians administering the drug, nor the patients or their caregivers knew whether a patient was getting the drug or the placebo.

The trial was later extended to a full 24 weeks, with similar results shown in terms of safety and clinical benefit.

Speaking in a Georgetown news release, Laura, the daughter of a woman enrolled in the trial, said that although she did not know whether her mother had received the treatment or placebo, "she seemed happier. We experienced joy. There were still moments of connection."

Reynolds did have one important caveat for caregivers, however.

Speaking in the news release, she stressed that the formulation used in the trial differs from commercially available THC or CBD. 

"People should not assume that products available at dispensaries or online are equivalent to what was studied in this trial," 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 trial was funded by a U.S. National Institutes of Health grant and by the Alzheimer’s Association. 

Because the findings were presented at a medical meeting, they should be considered preliminary until published in a peer-reviewed journal.

More information

For more on dementia-linked agitation, head to the U.S. National Institute on Aging.

SOURCE: Georgetown University Medical Center, news release, July 14, 2026