Marijuana, CBD and Alzheimer’s: Everything You Need to Know

As marijuana becomes more mainstream, and the CBD market thrives, can these herbal drugs treat people with Alzheimer’s and dementia? We take a deep dive into what we know and what researchers are still working to find out.

Why are medical professionals studying cannabis treatments for people living with dementia and Alzheimer’s disease? It’s expected that the rates of people living with dementia in the world will increase to 81.1 million by 2040, making new treatments to improve cognition and stress levels absolutely imperative.  The main symptoms of Alzheimer’s disease and related forms of dementia are cognitive decline, memory loss and behavior disorders. Scientists hope that the neuro-protective properties of marijuana will help people living with dementia and Alzheimer’s will actually repair damage, in addition to treating symptoms. 

Does marijuana affect Alzheimer’s disease?

It’s clear that researching marijuana for help with Alzheimer’s disease and dementia is an emerging science and there is a need for further studies. Research has found improvements in memory, especially with tetrahydrocannabinol (THC), even finding that the mice studied had less disease-progressing plaque that’s found in Alzheimer’s disease patients.

Studies have recently bridged over to human trials, including one developed by King’s College in London that’s exploring the effect of cannabis on dementia symptoms. Head researcher Chris Albertyn, discussed how he’s using Sativex, an oral medical marijuana spray, to see whether cannabis reduces agitation, aggression or confusion in a BrainTalk for Being Patient. 

He said, “Currently there is a scarcity of pharmacological treatments out there and some of them are damaging or dangerous, especially in the long-term. We’re looking for a safer and more effective alternative.”

Is marijuana legal?

While early cultures — and even Queen Victoria of England — used cannabis medically to alleviate pain and disease symptoms, marijuana was restricted for use in the United States during much of the 20th century. Recently, many states — including the West Coast, much of the American Southwest and a fair share of New England — have legalized the medical and even recreational use of marijuana or decriminalized being caught with cannabis. 

While this decision is being made at a state level, marijuana is at the time of this writing still considered illegal at the federal level. However, that too may be changing: the U.S. House of Representatives has passed legalization, and congress has formed a caucus to bring the production and distribution of marijuana under federal control, as opposed to the current state-by-state system. 

Meanwhile, cannabidiol (CBD) is legal in all 50 states, though the rules vary when it comes to its use, where it’s sourced from and the percentage of THC allowed. 

What are cannabinoids?

The plant that produces marijuana — cannabis — also produces a substance full of  compounds called cannabinoids, which can elicit certain reactions in the body.  Over 100 of these have been identified from studying cannabis, with CBD and THC, being the most studied.

There are specific receptors in the body that use cannabinoids to operate smoothly, including in the central nervous system. These receptors, known as CB receptors, directly affect short-term memory and coordination. 

Is CBD legal?

This is where legality gets even more complicated: Many cannabinoids are derived from hemp, and those are legal everywhere in the U.S. This has been the case federally since 2018, with the passage of the 2018 Farm Bill. CBD is derived from cannabis plants with a range of THC content, but is always legal as long as their THC content stays below 0.3%. 

Certain cannabinoids have been studied for their ability to kill tumors, prevent brain deterioriation and reduce pain and inflammation. Those results make cannabis research for Alzheimer’s disease an exciting possibility. 

What’s the difference between CBD and THC?

THC is the ingredient in marijana that is considered psychotropic. That means that marijuana with THC can change mood or behavior, even giving the user a sense of euphoria. Other psychotropic drugs can be found in pain medications, tobacco, even coffee. 

Cannabidiol or CBD, on the other hand, doesn’t cause any psychotropic, or behavior-altering symptoms. Products containing CBD, marketed for their therapeutic benefits, come in many forms, from snacks and drinks to salves to shampoo — to, even, products for your pets. 

Can CBD help with Alzheimer’s disease or dementia

Studies have reported changes in the endocannabinoid system in the brain of patients with Alzheimer’s disease, actually playing a role in the way Alzheimer’s develops, being shown to have neuroprotective properties, to reduce neuroinflammation, and to enhance the development of new brain cells as old brain cells die. 

A 2019 study found a clear benefit of treatment using CBD from cannabis to increase cell life and even stimulate growth in the hippocampus, an area in the brain that’s responsible for memory. It was found that combining CBD with THC was more effective at preserving brain function. The combination reduced damaging plaque and inflammation at a higher rate than CBD alone. 

Frequently, people living with Alzheimer’s disease and dementia experience agitation and low appetite. Marijuana has been found to stimulate appetite while reducing anxiety. 

However, experts maintain that so far, there aren’t enough studies  on people living with Alzheimer’s disease for doctors to recommend cannabis. The science is still emerging. 

Is CBD safe for people with dementia?

About seven out of 10 cases of Alzheimer’s are accompanied by symptoms of agitation and aggression. This could mean the patient experiences pacing, restlessness, shouting and screaming, even pushing or hitting. These behaviors — often triggered by stressful disruptions in daily life, like lack of sleep, a change in routine, other emotional distress — make an already-challenging journey all the more challenging. 

According to authors of a 2020 study published The Senior Care Pharmacist, a journal by the American Society of Consultant Pharmacists, evidence suggests that the utilization of marijuana products containing both THC and CBD alone “have been effective and safe for use in older people with agitation associated with dementia.” 

A 2017 review found that cannabinoids were shown to be safe particularly to address the dementia symptom of agitation, with few short-term side effects — an important differentiator from the prescription drugs — some of which are antipsychotics, which can be high-risk — available to treat this symptom.

However, “further research regarding the safety, efficacy, and variability of these products in older people is needed,” the study authors wrote in 2020. This is true especially because THC and CBD both do have drug-like interactions with the brain, and while the side-effects are thought to be lower-risk than those that come with prescription antipsychotics, for example, they do still have some side effects.

What are the side effects of marijuana?

The fact that marijuana is still illegal in some places aside, using marijuana as a symptomatic treatment for diseases like Alzheimer’s and dementia is complicated by its side effects.

According to the Centers for Disease Control and Prevention, it’s thought that the drug can have impacts on a developing brain in children and teens.  It has been linked to anxiety or depression in some groups, though this hasn’t been studied in those with Alzheimer’s disease. There are physical effects too, depending on the way it is consumed: Smoking the drug can cause damage to lung tissue.

What are the side effects of CBD?

Meanwhile, CBD has its side effects too: According to Harvard Health, it can cause drowsiness, dry mouth, and other mild symptoms. Those using this treatment should check with their doctor for any drug interactions. Herbal supplements may also interact with CBD.