A study conducted by researchers at the Johns Hopkins University School of Medicine and Tufts University School of Medicine, shows that a synthetic THC, known as dronabinol, has been shown to effectively reduce agitation in Alzheimer’s disease (AD) patients. The findings, presented at the International Psychogeriatric Association conference in Buenos Aires, demonstrated a 30% decrease in agitation symptoms among participants taking the medication.
Dronabinol is an FDA-approved synthetic version of THC, the principal psychoactive compound found in cannabis. Importantly, dronabinol did not cause patients to experience many of the common adverse drug effects such as delirium or seizures common in many current treatments for agitation.
Agitation affects about 40% of Alzheimer’s patients, which presents as increased motor activity, verbal aggression, and occasionally physical aggression.
“These new findings represent eight years of work dedicated to people who have Alzheimer’s as well as their caregivers,” said Paul Rosenberg, MD, a professor at Johns Hopkins and co-principal investigator of the study. He noted that agitation is one of the most challenging symptoms associated with Alzheimer’s, adding, “We are pleased to make positive strides forward in treatment of these patients.”
Brent Forester, MD, psychiatrist in chief at Tufts Medical Center and another co-principal investigator, added: “It is the agitation, not the memory loss, that often drives individuals with dementia to the emergency department and long-term-care facilities.”
Alzheimer’s disease is the most prevalent neurodegenerative disorder in the U.S. according to data from the National Institutes of Health. It estimates there are around 6.7 million cases of AD among in people aged 65 and older. This number is projected to rise in the future due to the aging population, to reach approximately 13.8 million by 2060.
For this research, the team recruited 75 patients with severe agitation from AD at five clinical sites, including 35 patients at the Johns Hopkins Hospital. Participants were selected based on a formal diagnosis of AD and exhibited significant agitation symptoms for at least two weeks prior to the trial. Researchers assessed baseline agitation using the Pittsburgh Agitation Scale (PAS) and the Neuropsychiatric Inventory Agitation/Aggression subscale (NPI-C).
The trial randomly assigning participants to receive either five milligrams of dronabinol or a placebo twice daily for three weeks. After this period, participants were retested using the same agitation assessments and a comparison of the two showed a reduction in PAS scores of those treated with dronabinol from an average of 9.68 to 7.26—a 30% decrease. The patients given placebo showed no change in their PAS scores.
The results of this study are particularly encouraging because dronabinol received FDA approval nearly 40 years ago from the FDA to treat loss of appetite in HIV/AIDS patients and is now commonly prescribed to treat the nausea and vomiting that can accompany cancer chemotherapy.
Based on these results, the researchers now plan to conduct a longer-term study involving larger patient cohorts and additional applications for the use of medical cannabis for managing symptoms in both patients and caregivers.
