Patients tolerated synthetic THC (dronabinol) well, without the adverse effects commonly associated with existing Alzheimer’s agitation medications.
A study conducted by researchers from Johns Hopkins University School of Medicine and Tufts University School of Medicine found that a pill form of dronabinol, an FDA-approved synthetic version of THC (the main ingredient in marijuana), reduces agitation in Alzheimer’s patients by an average of 30%.
The researchers say that compared to current treatments for agitation, such as antipsychotics, dronabinol produced similar calming effects without adverse results such as delirium or seizures.
Results of the eight-year clinical trial were presented at the International Psychogeriatric Association conference in Buenos Aires, Argentina, on Sept. 26.“These new findings represent eight years of work dedicated to people who have Alzheimer’s as well as their caregivers,” says Paul Rosenberg, M.D., professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine and co-principal investigator for this study. “Agitation is one of the most distressing symptoms of Alzheimer’s dementia, and we are pleased to make positive strides forward in the treatment of these patients.”
Alzheimer’s Agitation and the Need for New Treatments
Alzheimer’s disease is the most common neurodegenerative disease in the United States, with an estimated 6.7 million cases in Americans age 65 and older, according to the National Institutes of Health. This number is predicted to grow to 13.8 million by 2060. Agitation is difficult to manage. It is defined as excess motor activity (pacing or repetitive movements), verbal aggression, and/or physical aggression. An estimated 40% of people with Alzheimer’s develop agitation.
Although mild agitation can sometimes be moderated by behavioral intervention, in moderate to severe cases, some form of medication is typically required to manage symptoms and provide relief for caregivers.“It is the agitation, not the memory loss, that often drives individuals with dementia to the emergency department and long-term-care facilities,” says Brent Forester, M.D., psychiatrist-in-chief and chairman of the Department of Psychiatry at Tufts Medical Center and co-principal investigator on the study. “Dronabinol has the potential to both reduce health care costs and make an important, positive impact on caregivers’ mental and physical health.”
In the new study, researchers recruited 75 patients with severe Alzheimer’s agitation across five clinical sites, including 35 admitted to The Johns Hopkins Hospital between March 2017 and May 2024. To qualify, patients had to have a formal clinical diagnosis of Alzheimer’s disease and show at least one major symptom of agitation for at least two weeks. Prior to treatment, patients were tested for agitation using the Pittsburgh Agitation Scale (PAS) and the Neuropsychiatric Inventory Agitation/Aggression subscale (NPI-C).
The PAS scores agitation from 0 to 4, with 4 being the most agitated. The NPI-C provides a brief assessment of neuropsychiatric symptoms including delusions, hallucinations, anxiety/depression, and other factors. Baseline scores were acquired from caregivers at the onset of the trial.
Participants were then randomly selected to get either 5 milligrams of dronabinol in pill form or a placebo in pill form twice daily for three weeks, and then retested using the PAS and NPI-C.
Future Research and Cautions
Results from the dronabinol group show an average PAS starting value of 9.68 and an end value of 7.26 after three weeks, a 30% decrease compared to the scores in the placebo group which did not change. Additionally, dronabinol was well tolerated by patients compared to current treatments for agitation.“Results like this are encouraging. We are thrilled that FDA-approved dronabinol was robustly effective and appeared safe for treatment of agitation,” says Rosenberg. “This adds another tool in our efforts to improve the care of our loved ones with Alzheimer’s disease.”
The researchers say they plan longer-term studies of dronabinol for Alzheimer’s disease, as well as expanded sample sizes. They also hope to continue to explore other ways medical cannabis can benefit both patients and caregivers.
Dronabinol is a synthetic form of THC, the psychoactive main ingredient in cannabis (marijuana). The drug was approved by the U.S. Food and Drug Administration in 1985 to treat loss of appetite in patients with HIV/AIDS, and is currently prescribed to treat nausea and vomiting in those undergoing cancer chemotherapy.
The investigators caution that their current study results are not intended to encourage or inform the use of other forms of medical marijuana available in 38 states and the District of Columbia.
Meeting: International Psychogeriatric Association conference
Co-investigators include Halima Amjad, Haroon Burhanullah and Milap Nowrangi at the Johns Hopkins University School of Medicine, Marc Agronin at Miami Jewish Health, and James Wilkins and David Harper at McLean Hospital.
The study was funded by a grant from the National Institute of Aging at the National Institutes of Health.
News
Annual blood test could detect cancer earlier and save lives
A single blood test, designed to pick up chemical signals indicative of the presence of many different types of cancer, could potentially thwart progression to advanced disease while the malignancy is still at an early [...]
How the FDA opens the door to risky chemicals in America’s food supply
Lining the shelves of American supermarkets are food products with chemicals linked to health concerns. To a great extent, the FDA allows food companies to determine for themselves whether their ingredients and additives are [...]
Superbug crisis could get worse, killing nearly 40 million people by 2050
The number of lives lost around the world due to infections that are resistant to the medications intended to treat them could increase nearly 70% by 2050, a new study projects, further showing the [...]
How Can Nanomaterials Be Programmed for Different Applications?
Nanomaterials are no longer just small—they are becoming smart. Across fields like medicine, electronics, energy, and materials science, researchers are now programming nanomaterials to behave in intentional, responsive ways. These advanced materials are designed [...]
Microplastics Are Invading Our Arteries, and It Could Be Increasing Your Risk of Stroke
Higher levels of micronanoplastics were found in carotid artery plaque, especially in people with stroke symptoms, suggesting a potential new risk factor. People with plaque buildup in the arteries of their neck have been [...]
Gene-editing therapy shows early success in fighting advanced gastrointestinal cancers
Researchers at the University of Minnesota have completed a first-in-human clinical trial testing a CRISPR/Cas9 gene-editing technique to help the immune system fight advanced gastrointestinal (GI) cancers. The results, recently published in The Lancet Oncology, show encouraging [...]
Engineered extracellular vesicles facilitate delivery of advanced medicines
Graphic abstract of the development of VEDIC and VFIC systems for high efficiency intracellular protein delivery in vitro and in vivo. Credit: Nature Communications (2025). DOI: 10.1038/s41467-025-59377-y. https://www.nature.com/articles/s41467-025-59377-y Researchers at Karolinska Institutet have developed a technique [...]
Brain-computer interface allows paralyzed users to customize their sense of touch
University of Pittsburgh School of Medicine scientists are one step closer to developing a brain-computer interface, or BCI, that allows people with tetraplegia to restore their lost sense of touch. While exploring a digitally [...]
Scientists Flip a Gut Virus “Kill Switch” – Expose a Hidden Threat in Antibiotic Treatment
Scientists have long known that bacteriophages, viruses that infect bacteria, live in our gut, but exactly what they do has remained elusive. Researchers developed a clever mouse model that can temporarily eliminate these phages [...]
Enhanced Antibacterial Polylactic Acid-Curcumin Nanofibers for Wound Dressing
Background Wound healing is a complex physiological process that can be compromised by infection and impaired tissue regeneration. Conventional dressings, typically made from natural fibers such as cotton or linen, offer limited functionality. Nanofiber [...]
Global Nanomaterial Regulation: A Country-by-Country Comparison
Nanomaterials are materials with at least one dimension smaller than 100 nanometres (about 100,000 times thinner than a human hair). Because of their tiny size, they have unique properties that can be useful in [...]
Pandemic Potential: Scientists Discover 3 Hotspots of Deadly Emerging Disease in the US
Virginia Tech researchers discovered six new rodent carriers of hantavirus and identified U.S. hotspots, highlighting the virus’s adaptability and the impact of climate and ecology on its spread. Hantavirus recently drew public attention following reports [...]
Studies detail high rates of long COVID among healthcare, dental workers
Researchers have estimated approximately 8% of Americas have ever experienced long COVID, or lasting symptoms, following an acute COVID-19 infection. Now two recent international studies suggest that the percentage is much higher among healthcare workers [...]
Melting Arctic Ice May Unleash Ancient Deadly Diseases, Scientists Warn
Melting Arctic ice increases human and animal interactions, raising the risk of infectious disease spread. Researchers urge early intervention and surveillance. Climate change is opening new pathways for the spread of infectious diseases such [...]
Scientists May Have Found a Secret Weapon To Stop Pancreatic Cancer Before It Starts
Researchers at Cold Spring Harbor Laboratory have found that blocking the FGFR2 and EGFR genes can stop early-stage pancreatic cancer from progressing, offering a promising path toward prevention. Pancreatic cancer is expected to become [...]
Breakthrough Drug Restores Vision: Researchers Successfully Reverse Retinal Damage
Blocking the PROX1 protein allowed KAIST researchers to regenerate damaged retinas and restore vision in mice. Vision is one of the most important human senses, yet more than 300 million people around the world are at [...]
