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Curious About the Relationship between Cannabis and Dementia?

Updated: Oct 6, 2022

by Teepa Snow, MS, OTR/L, FAOTA

As the US and Canada have opened the door to recreational and medical use marijuana, those who are caring for someone living with dementia are considering using some form of cannabis to help with one of more of the following symptoms:

  1. Distress – emotional or physical

  2. Sleep disturbances or insomnia

  3. Social discomfort or anxiety

  4. Appetite loss

  5. Anger about situation, care, or options being provided by life or care situation

  6. Fear or sense of isolation due to changes in social support, availability of social support, or limits of those around to respond to requests or demands

  7. Confusion about where the person is or where they should be or what they should be doing

  8. Confusion about when in their life they are and who they should be around or finding in their world

In my experience, as with any drug or medication, there are pluses and minuses to consider before diving head first into the pool. Additionally, the sources from which you get the medication or drug, the dosage strength and frequency, as well as, the route of delivery may very well matter.

To start let’s review what we know about cannabis as an aid to help with these various symptoms in the general population, since the studies that are investigating the value of various forms of cannabis are in their infancy for people living with various forms and degrees of dementia.

To get started let’s work on a few vocabulary words that might be important to know about:

Anecdotal – a single person reporting on their experience, a single case report by a provider, or professional, or a report from a practitioner who has worked with several people, but has not actually conducted a study or collected specific evidence to compare other treatments, placebo treatments, or collected a panel of information about the person beyond the immediate impact on a particular symptom. At this point in the US and Canada, most of the information that is available is still at the anecdotal level, as the clinical trials and studies are just getting started.

Clinical Trials – formal scientific studies that compare the impact of the chemical on one group of people who are taking the medication or drug, to the impact of taking a placebo or not taking anything on a similar group of people. Sometimes the groups get reversed over time and sometimes they do not. In either case, the goal is to try to keep everything else the same, except the drug or treatment, so that cause and effect can be linked. Although there are some internationally available studies on cannabis and various patient populations, there is very little available at this time related to people living with various dementias. This is primarily due to the historical view that marijuana was just a recreational drug and had been banned in the US as a legal substance for generations.

Psychoactive – chemical that when taken in by humans in some way (breathed in, eaten, applied, swallowed), causes altered perceptions in some or all of the following areas of physical movement or sensation, vision, hearing, time, space, or relationships/interactions.

There are many chemicals that come from cannabis. These chemicals are called cannabinoids as a group, each however, is unique. You will want to know about and understand what each is and what it potentially does. Some of these are abbreviated as CBD, THC, CBN, and CBG. Some occur in the marijuana plant while others are formed when the resin is heated or extracted.

A. CBD – cannabidiol – non-psychoactive element, in other words it does not alter your perceptions of the world around you in a strong or exciting way. It has been demonstrated in preliminary studies, as well as anecdotally reported, to help in the treatment of nausea, anxiety, insomnia, convulsions, and various inflammations.

B. THC – Delta9-tetrahydrocannabinol – psychoactive element, it alters perceptions and may heighten and intensify many senses and experiences. Anecdotally, THC has been noted to: reduce or eliminate various types of pain, aid in relaxation, produce euphoric (positive and strong emotional reactions/sensations or effects), increase appetite, and possibly protect, neurologically, at least some functional areas of the brain.

C. CBN – cannabinol – mildly psychoactive, it typically reduces anxiety while producing an elevation of mood at the same time. It has been used anecdotally to aid with sleep by making you feel sleepy, helping you stay more deeply asleep, and aids in preventing anxiety.

D. CBG – cannabigerol – non-psychoactive – considered to be a pre-defined or modified form or preliminary form of the two resulting chemicals THC and CBD. Some researchers are beginning to study carefully this form of cannabis to treat neurological conditions, skin conditions, chronic pain, and other concerns. It appears to act on specific site receptors throughout the body and may be helpful, without causing the mental state alterations that THC causes. Some studies have indicated it has impact on the serotonin system, so may have impact on depression. Some preliminary investigations have noted the following possible benefits: stimulates bone formation and healing, slows tumor growth, treats fungal or bacterial infections, relieves pain, reduces inflammation, calms overactive bladders, reduces the impact of glaucoma, decreases anxiety, reduces depressive symptoms, and can be neuroprotective for mice altered to have Huntington’s disease.

When it comes to treating dementia with cannabinoids, there is still a good bit of work to be done. This past year, however, one study on mice found that a synthetic form of THC kept the mice from building up plaque at the rate those who did not get the chemical did. It also allowed them to be able to perform the tests as well as mice who did not have the dementia symptoms. This article was reported on, at the BeingPatient website, by Emily Woodruff on November 7, 2018.

There is also a newly approved study underway by the University of Saskatchewan. They will be looking at cannabis in the treatment of various pain issues related to dementia.

Warning – Alert – Be Careful

As with any medication, individual reactions and responses can vary widely and wildly! Just because one person benefits from eating candy with a specific dosage of CBD or THC chemical in it, at set intervals, at specific times, it does not mean another person will have the same responses or reactions.

We have no data at this point, that would cause me, personally, to begin consuming any dosage of some form of cannabis to keep my brain fit and well. Many have been tricked before by the promises of protection with vitamin E, and gingko, only to find it actually had no benefit.

I, personally have heard of success stories, as well as problematic situations when cannabinoids are used. Data seems to be mixed. There is also mixed information on which form of cannabis should be used by which person for what symptom, under which circumstance, and at what dosage. Certainly, given the challenges that many drugs pose for PLwD, it might be worth a trial with a target in mind and some measurement system being used. This is particularly true for people living with Lewy Body disease and insomnia, high levels of distress and anxiety, problems with eating, difficulty with pain, or severe visual disturbances or thinking issues that are very disturbing for that person. For that group, more traditional medications can and do cause tremendous harm and problems. Considering this option may be less risky than some other alternatives. It would, however, be important to have a supply source that is both reliable and consistent in quality and intensity for the safety of all involved.

As with so many medications and drugs, it really is a buyer/manager beware situation. If it is too good to be believed… then it is probably not true… It more than likely is either a lie, or a partial truth. Get prepared before you move forward, if you determine that this course of action would work better than what you have now, then proceed with caution. But please, build a team, so you can move forward with awareness, knowledge, and some skill.

As time passes and more people use the various options, we will undoubtedly become more aware and knowledgeable about what makes sense. Given the massive and deadly fentanyl and opioid epidemic gripping both the US and Canada at the moment, as well as drug surprises from our past, I would urge some degree of caution and taking precautions to minimize risk while seeking benefit.

Resources used for this article:

Medscape Website (you will need to create a user id if you wish to read)

Reprinted with Permission.  For more information, visit



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