Today, there is much discussion about how cannabis and cannabis-derived products can treat a range of health conditions, including glaucoma, epilepsy, and cancer. But is there scientific evidence to support these claims? And can marijuana be used as a treatment for Alzheimer’s?

Some members of myALZteam have shared their experiences with cannabis. One member described tetrahydrocannabinol (THC), a compound in cannabis, a “a lifesaver” for their spouse. Another member noted that medical marijuana helped reduce their stress as a caregiver: “Medical marijuana has been a godsend … for me!”

This article will cover the basics of medical marijuana and its potential benefits for those living with Alzheimer’s.

What Is Medical Marijuana?

Medical marijuana refers to the use of cannabis, a plant known for its mind-altering effects, primarily derived from Cannabis sativa and Cannabis indica. The active compounds in marijuana are called cannabinoids, with the most well-known being tetrahydrocannabinol (THC) and cannabidiol (CBD).

In the United States, marijuana is classified as a Schedule I controlled substance, meaning federal law prohibits its use for any purpose. However, many states have legalized marijuana to varying degrees, leading to different regulations across the country.

For instance, states like Indiana only permit CBD with less than 0.3 percent THC, provided it’s derived from hemp rather than marijuana. Meanwhile, in neighboring Illinois, individuals can legally purchase up to 30 grams of marijuana and products containing up to 500 milligrams of THC.

Although marijuana itself is not approved for medical use by the U.S. Food and Drug Administration (FDA), certain cannabinoid-based products are. These include:

• Dronabinol (synthetic THC) — Used to treat nausea or vomiting caused by chemotherapy
• Syndros (synthetic THC) — Used to treat weight loss in people with anorexia
• Epidiolex (CBD) — Used to treat Dravet syndrome and Lennox–Gastaut syndrome, which are forms of epilepsy

The FDA hasn’t approved marijuana, CBD, or synthetic THC for treating Alzheimer’s. However, some states have authorized medical marijuana for Alzheimer’s disease. Be sure to check the laws in your area.

Can Marijuana Prevent Alzheimer’s?

Cannabinoids may help protect the brain from dementia. This protection might reduce the risk of developing Alzheimer’s and other neurodegenerative diseases. In an animal study, cannabinoids were shown to reduce amyloid plaques in the brain.

Amyloid plaques are among the two main proteins linked to Alzheimer’s disease. The buildup of these plaques causes the progression of the disease. Plaques initially form in the area of the brain that controls memory. As the plaques spread, they damage nerve cells and brain tissue. Therefore, reducing these amyloid plaques could protect against Alzheimer’s.

However, there is also evidence suggesting that cannabinoids can impair memory and affect learning. Most of these studies focus on younger populations rather than older adults. Younger individuals, whose brains are still developing, may be more vulnerable to the effects of marijuana. One theory suggests that taking lower doses at an older age might reduce potential negative effects while increasing positive outcomes.

Currently, all research on cannabinoids and dementia prevention has been conducted in labs or on animals — no research has been done in humans. While the research is promising, human studies are needed to determine whether marijuana can prevent Alzheimer’s.

What Are the Potential Benefits of Marijuana for Alzheimer’s?

There has been no research on the effectiveness of cannabinoids for Alzheimer’s prevention in humans. However, some smaller studies have explored their potential for treating symptoms of Alzheimer’s. Recent research shows that cannabinoids may help reduce symptoms like agitation.

In a 2022 study, 19 people living with dementia were treated daily with THC and CBD. Before starting treatment, researchers measured agitation, difficulty with daily activities, and behavioral issues. They then measured the same behaviors while participants were receiving treatment. The results showed that treatment reduced agitation and made daily activities, such as personal care, easier.

The people living with Alzheimer’s weren’t the only ones positively affected by the treatment. According to the researchers, “caregivers … particularly appreciated the improved quality of contact with their patients.”

Another study involving nabilone (a synthetic THC that requires a prescription) also showed a decrease in agitation and reduced caregiver distress.

While these findings are promising, the 2022 study and the nabilone study only tested 19 and 39 people, respectively, for a total of 58 participants. Many studies on cannabinoids and dementia are too small to determine if their findings apply to the broader population. To address this issue, researchers often group studies together in reviews.

Review studies on cannabinoids and dementia show that results are not conclusive yet. Two similar studies published in 2019 and 2020 found that there isn’t enough evidence to support the use of cannabinoids. A study published in 2019 reported more promising findings. However, the researchers noted that the data was weak.

Most studies published so far have involved small groups of people over short periods. These studies are preliminary. More research is needed to truly determine if cannabinoids can treat Alzheimer’s symptoms.

With further research, experts will be better equipped to determine whether cannabinoids can help relieve symptoms of Alzheimer’s. Be sure to ask your loved one’s doctor about medical marijuana and other strategies for managing their symptoms.

Is Marijuana Safe for People Living With Alzheimer’s?

We still don’t know if marijuana can help with symptoms like agitation for people living with Alzheimer’s. However, it’s important to weigh the risks against the potential benefits.

Studies show that cannabinoid treatment has no serious side effects. For example, a 2019 review looked at trials for both synthetic THC and natural THC. The review found no increases in negative health events related to cannabinoid treatments.

A second 2019 review study showed similar results. This study also included findings on natural THC and synthetic THC. The only adverse effect linked to cannabinoids in these studies was lethargy, meaning that the drug caused sleepiness or inactivity.

It’s important to note that cannabinoids can have an effect on other drugs a person is taking. Before adding a new treatment, check in with your loved one’s doctor about potential drug interactions.

What Are the Current Recommendations for Using Marijuana With Alzheimer’s?

According to the Alzheimer’s Association, there is “lots of hype, little evidence” regarding the use of cannabis for Alzheimer’s treatments. The Alzheimer’s Society also agrees that “more research is needed.”

The symptoms of Alzheimer’s can be tough on family members and caregivers. One myALZteam member shared, “I don’t know how to deal with this. I feel like I’m walking on eggshells. … I’m not enjoying life because I’m afraid to make them angry.”

While there are other ways to manage outbursts, trying marijuana to reduce symptoms may feel like the next right choice for you and your loved one.

If you’re considering marijuana as a treatment option for your loved one, remember to involve their doctor. They can help predict possible side effects or interactions with other medications. Also, be sure to check what types of treatment are legal in your area.

Talk With Others Who Understand

On myALZteam, the social network for caregivers of people with Alzheimer's disease, more than 86,000 members come together to ask questions, give advice, and share their stories with others who understand life with Alzheimer’s.

Are you curious about what marijuana medical options others are trying? Or have you tried medical marijuana to manage your loved one’s symptoms? Share your experience in the comments below, or start a conversation by posting on your Activities page.