Medical THC and CBD formulation significantly reduces late-life dementia agitation

In a first-of-its-kind clinical trial, U.S. researchers have found that people with agitation and dementia in late life who took a special medical formulation of two active ingredients found in marijuana – THC and CBD – had significantly less agitation compared to people who received a placebo.

The primary findings of the study were presented July 14, 2026, at the Alzheimer's Association International Conference in London by Jacobo Mintzer, MD, of the and Medical University of South Carolina and Georgetown University's Brigid Reynolds, MSN, APRN, ANP-BC.

The study, dubbed the LiBBY trial (Life's end Benefits of cannaBidiol and tetrahYdrocannabinol), enrolled 120 participants with Alzheimer's disease or other types of dementia who were hospice-eligible and experiencing agitation. Ten medical centers nationwide conducted the LiBBY study visits at participants' homes or places of residence. Close to 90% of study participants who received the treatment showed overall improvement after 12 weeks.

These trial results were extremely impressive and showed a level of response not seen before in clinical trials related to dementia. Rarely do we see close to 90% of patients in a trial respond positively to a new medication."