Ask Dr. Leigh: can cannabis help dementia patients?

cannabis for dementia holding hands

Using cannabis can have a big impact on your physical and mental health—for better, and once in a while, for worse. That’s why it’s important to consult a healthcare provider before experimenting.

Here at GreenState, cannabis clinician Dr. Leigh Vinocur is here to answer your questions on healthy living with cannabis.

Editor’s Note: The answer to this question is meant to supplement, not replace, advice, diagnoses, and treatment from a healthcare provider.  Always consult a medical professional when using cannabis for medicinal purposes, and do not disregard the advice of your healthcare provider because of anything you may read in this article. 

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Q) Can cannabis help my family member with dementia?

Medical cannabis and its potential therapeutic application for dementia is currently an active area of scientific research. We know that cannabis can be a neuroprotective; it has anti-inflammatory and antioxidant possibilities. It is being studied as a target for traumatic brain injury (TBI) and other neurodegenerative diseases, such as Parkinson’s and Alzheimer’s disease

A 2020 study found that CBD increased blood flow in the brain within the hippocampus, which is important in memory processing and learning. Because of this, researchers are looking into its use in dementia patients. 

Historically, some of the first studies were done as far back as 1997. Researchers used a legal synthetic THC called dronabinol (brand name Marinol), looking at appetite and agitation in Alzheimer’s patients. It was a small, short-term study but was a placebo-controlled trial, meaning one group got the drug dronabinol, and the other got a fake treatment without THC, such as a “sugar pill.”  

The researchers looked at two very common problems seen in dementia patients: anorexia due to not wanting to eat, as well as disturbed behaviors like agitation. They found that patients in the treatment group had increased appetite and gained weight, as well as had decreased agitation that even persisted after they stopped the treatment.  Another study in 2006 using dronabinol corroborated those results with a decrease in nighttime agitation in patients with severe dementia.

Some subsequent studies have also shown promise. An Israeli study from 2016 used plant-based medical cannabis oil containing THC. They found a significant decrease in behavioral issues such as delusions, irritability, agitation, and aggression. They also found enhanced sleep patterns, reduced apathy with better social engagement, leading to less caregiver distress, which can’t be underestimated.

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Cannabis benefiting dementia caregivers, too

Dementia patients are a vulnerable population whose health and safety depend on caregivers. Caring for dementia patients is extremely stressful, whether it is a family member or a healthcare provider. According to the Alzheimer’s Association, over 60 percent of caregivers report high stress levels, with 40 percent reporting anxiety and depression. Studies have shown that disruptive behaviors in dementia patients significantly contribute to this stress and can contribute to cardiovascular risk in chronic caregivers. 

A small 2019 study from Switzerland looked at cannabis’ effect on behavioral issues in institutionalized severe dementia patients but also addressed the issue of caregiver distress. It was done using an oral cannabis preparation of THC/CBD in an approximate 1:2 ratio. They escalated the dose over two months. 

At the end of those two months, more than half of the patients could decrease or stop their psychotropic drugs, which are often used for behavioral issues but can be dangerous in this elderly population of patients.  They were also able to use less opioids for pain. 

Researchers also found improved behaviors and engagement with staff, which lasted more than two months. In fact, the study’s author stated that initially, the nurses were skeptical. Still, they started to notice decreased muscle rigidity, which made it easier to bathe and transfer patients in and out of bed. 

The study team described the patients as being calmer, more relaxed, less irritable, and even smiling more. Several patients who had been continuously screaming stopped completely.  One patient stopped continuously vomiting, and by stopping the opioids, the nurses noticed less constipation, which is an issue when caring for bed-ridden nursing home patients. Overwhelmingly, the feedback from the families of these patients was also positive.

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Long-term impacts of cannabis on dementia

In 2022, the same group of Swiss researchers published another study, this time observing patients long-term over two years. They found patients’ clinical and behavioral symptoms were improved and remained stable long-term. And despite many of these patients requiring multiple medications, even long-term, there were no serious drug-drug interactions or side effects. Patients tolerated cannabis well as an adjunct treatment in this population of severe dementia patients.  

A recent study just published in 2023 was done in Italy. They examined dementia patients using a medical cannabis oil extract that was THC-dominant (THC 22%/ CBD 0.5%) taken twice a day for 12 weeks. They found improvement in behavioral symptoms in all patients, such as less physically and verbally aggressive behaviors. They also found less apathy, agitation, irritability, sleep and eating disturbances. And this, in turn, also led to less caregiver distress. 

This study used an exam called the Mini Mental Status Exam, a validated questionnaire that physicians use to assess cognitive impairment, detecting problems in thinking, communication, understanding, and memory. Remarkably, 45 percent of the patients exhibited cognitive enhancement, with improvements in language, recall, complex commands, and calculations, and being more aware of place and time. This is notable because today, all the pharmaceutical drugs we have for Alzheimer’s and other dementias can only slow cognitive decline; none yet have been found to improve cognition. 

While all of these findings are promising, it’s crucial to approach this with caution due to the small sample size and observational nature of most studies with no placebo group, which is considered the gold standard for research today. It’s also worth noting the diversity of diseases and conditions that cause dementia because there may not be a single beneficial therapeutic regime for all of the different causes. And, of course, as with any potential medical intervention, it’s imperative to consult a physician before considering medical cannabis for your loved ones with dementia.

Got cannabis questions? Ask Doctor Leigh. Send your questions to GreenState’s Editor at and keep an eye out for new answers from Dr. Leigh Vinocur every month.

Dr. Leigh Vinocur is a board-certified emergency physician who also has a cannabis consulting practice for patients and industry. She is a member of the Society of Cannabis Clinicians and a graduate of the inaugural class, with the first Master of Science in the country in Medical Cannabis Science and Therapeutics from the University of Maryland School of Pharmacy.

The response to this question was not written or edited by Hearst. The authors are solely responsible for the content.