Public Release: 

Medical marijuana pill may not be effective in treating behavioral symptoms of dementia

Study suggests drug dosage safe and well-tolerated in trial

American Academy of Neurology

MINNEAPOLIS - A new study suggests that medical marijuana pills may not help treat behavioral symptoms of dementia, such as aggression, pacing and wandering. The research is published in the May 13, 2015, online issue of Neurology®, the medical journal of the American Academy of Neurology. However, researchers did find that the drug dosage used in the clinical trial was safe and well-tolerated.

"Our study results are valuable since any firm evidence of the effectiveness and safety of medical marijuana in this disease area is scarce," said study author Geke A.H. van den Elsen, MD, with Radboud university medical center in Nijmegen, the Netherlands. "Ours is the largest study carried out so far on evaluating this drug for behavioral symptoms of dementia."

For the study, researchers randomly selected 50 participants with dementia and behavioral symptoms to receive 1.5 milligrams of medical marijuana or a placebo pill three times per day for three weeks. The medical marijuana pill contained tetrahydrocannabinol (THC), which is the main chemical involved in marijuana's psychoactive effects. The main study measurement was change in scores on a test of behavioral symptoms called the Neuropsychiatric Inventory, assessed at the start of the study and after two and three weeks.

The test scores improved for both the medical marijuana and the placebo groups, but there was no significant difference between the scores for the two groups. There was also no difference between the two groups for participants' quality of life, daily living activities or pain-related behavior and pain intensity.

Van den Elsen said improvements in the placebo group could be due to several factors, including attention and support from the study personnel, expectations of patients and caregivers and training of nursing home personnel.

People in the two groups had a similar number of mild and moderate side effects. There were no serious side effects in either group.

"Since the side effects were mild to moderate, it's possible that a higher dose could be tolerated and could possibly be beneficial," said van den Elsen. "Future studies are needed to test this. A drug that can treat the behavioral symptoms of dementia is much needed, as about 62 percent of dementia patients in the general community and up to 80 percent of nursing home residents experience these symptoms."


The study was supported by the European Regional Development Fund and the Province of Gelderland. The drug was provided by Echo Pharmaceuticals, Weesp, the Netherlands.

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The American Academy of Neurology, an association of more than 28,000 neurologists and neuroscience professionals, is dedicated to promoting the highest quality patient-centered neurologic care. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer's disease, stroke, migraine, multiple sclerosis, brain injury, Parkinson's disease and epilepsy.

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