What to Know About Marijuana and Parkinson’s Disease as CAM Therapy

People with Parkinson's disease are becoming more interested in learning how medical marijuana and cannabidiol (CBD) can relieve symptoms associated with the disease. Medical marijuana is a type of complementary and alternative medicine (CAM) that has not traditionally been used in the medical community.

But in recent years, more states have authorized the use of marijuana for both recreational and medicinal use. As a result, Parkinson's patients are asking their physicians if medical cannabis is an effective treatment for their disease.

Parkinson's disease is a neurodegenerative disease with no cure, but some studies have shown that medical marijuana helps relieve symptoms. Learn more about the benefits and considerations that come with using marijuana as a therapy for Parkinson's disease.

What Is Medical Marijuana?

Medical marijuana is cannabis that's prescribed by a physician to treat or provide relief for a medical condition.

There are around 400 chemicals in the cannabis plant, and more than 60 of them are referred to as “cannabinoids.” The “high” marijuana users get is primarily due to the most psychoactive cannabinoid in the plant called tetrahydrocannabinol, or THC. 

Cannabinol, or CBD, is the other cannabinoid, which is used in medical marijuana. CBD does not cause a “high” when taken alone and, in fact, moderates the psychoactive effects. Research is being done to determine how medical marijuana can help treat or relieve symptoms of various diseases, including Parkinson's disease.

How Does Medical Marijuana Affect the Body?

Marijuana affects the body through neurotransmitters, which are the chemical messengers of the nervous system.

Various factors can stimulate neurotransmitter activity, initiating a set of physiological responses. In cannabis, it is mainly THC or CBD binding to endocannabinoid receptors that produce new physiological reactions in the body.

The endocannabinoid system (ECS) is one of the most important neurotransmitter systems in the body. It utilizes cannabinoid receptors located throughout the central nervous system (CNS) and peripheral nervous system (PNS). Cannabis works to “turn on” endocannabinoid neurotransmitters through activity at these receptors.

There are two types of cannabinoids involved in cannabis use:

• Endocannabinoids are chemical messengers that affect the cannabinoid receptors in humans and animals. "Endo" means produced in the body system.
• Phytocannabinoids are chemical messengers found in cannabis and hemp plants. "Phyto" refers to plants.

Cannabis and hemp are legally classified based on THC content. Hemp is a plant that contains 0.3% or less THC. Cannabis plants contain more than 0.3% THC.

How THC and CBD Work

Cannabinoids from cannabis activate the ECS by binding to endocannabinoid receptors throughout the brain and body. The two most affected by cannabis are:

• CB1 receptors: Found in the brain in high levels, they are responsible for marijuana’s psychoactive properties, or the “high” effect.
• CB2 receptors: Found throughout the body, they affect pain levels and inflammation.

THC strongly activates CB1 receptors, triggering a feeling of euphoria. This activation also increases blood flow to the prefrontal cortex of the brain, which is the area that controls the ability to focus, as well as our motor skills, attention, memory, and decision-making abilities.

THC also interacts with CB2 receptors, providing added analgesic (pain relieving), muscle relaxing, and antiemetic effects (helping with nausea and vomiting).

CBD activates both CB1 and CB2 receptors, although less strongly than THC. Although its CB1 and CB2 receptor activation does not produce a “high,” it has been shown to interact with additional receptors in the body and have calming and anti-inflammatory effects. For this reason, CBD has been used to treat pain, anxiety, and seizures.

Medical Marijuana as a Treatment for Parkinson’s Symptoms 

Parkinson’s disease is a disorder of the central nervous system that causes tremors, slow movement, stiffness, and loss of balance. Because marijuana directly affects the central and peripheral nervous systems, scientists have studied the effect of marijuana as a treatment for Parkinson’s symptoms.

A 2020 review of 14 different studies acknowledged evidence that medical marijuana provides a reduction in anxiety, tremors, and involuntary or erratic movements. However, the researchers concluded that there is insufficient evidence to recommend medical marijuana use as part of Parkinson's treatment.

A 2017 study with patients who used medical marijuana over three months to manage Parkinson's symptoms found that the treatment improved their symptoms and did not cause major adverse effects.

Other research has shown that medical marijuana may be able to help with some Parkinson’s disease symptoms, including:   

• Bradykinesia (decreased movement ability)
• Rigidity
• Tremors
• Sleep problems
• Pain

Cannabis use for patients with Parkinson's has also been shown to help improve mood, memory, and fatigue.

Possible Benefits 

Medical marijuana use can provide additional benefits for patients with Parkinson's, including symptom relief for:

• Anxiety
• Pain
• Poor sleep
• Nausea

Possible Side Effects

As with any medication, there are potential side effects of medical marijuana. Negative effects of medical marijuana use for Parkinson’s can include:

• Cognitive impairment, such as issues with attention, focus, and memory
• Increased appetite and weight gain
• Depression
• Lung damage (if smoking)
• Increased heart rate
• Dependence or potential withdrawal symptoms
  

How to Use Cannabis for Parkinson’s 

There are many ways to use medical marijuana. If you are considering using medical marijuana to treat Parkinson's symptoms, speak with your physician about the best products and applications for your specific case.

Forms of medical marijuana include:

• Tinctures
• Capsules
• Lozenges
• Dermal patches
• Dermal sprays
• Edibles
• Vaporizing
• Smoking

Dosage 

There is no universal marijuana or CBD dosage. Studies are being done to determine how patients respond to the effects of marijuana differently. Longer clinical trials with more patient involvement are needed to establish dosage parameters, so speak to your physician about the right dosing options for you.

Legality 

Medical marijuana is legal in 36 states and four territories as of May 2021. There are some restrictions regarding THC content in many states.

Recreational marijuana is legal in 18 states, two territories, and the District of Columbia as of July 2021.

Although CBD does not produce a psychedelic effect, it is not legal in all 50 states, even if it's sourced from hemp containing less than 0.3% THC. The reason is that each state has its own Controlled Substances Act (CSA) that considers CBD to be marijuana in some states.

Considerations Before Buying Marijuana Products 

Marijuana is a Schedule 1 drug, meaning that it is a drug with a high potential for abuse and no currently accepted medical use. For that reason, it is still illegal to use in much of the country.

If you are considering using marijuana for medical purposes, there are a few things you need to consider, such as:

• THC and CBD content levels
• Published and accessible Certificates of Analysis (CoA), which certify the test results of the product from the manufacturer
• Organic vs. not
• Where it's sourced
• Methods of consumption

A Word From Verywell

Living with Parkinson’s disease can be challenging and stressful. While there are treatments available to help you manage your symptoms, you may want to discuss the possibility of medical marijuana as part of your treatment plan. Before taking any medication for symptom management, discuss your options with your physician, and whether medical marijuana is appropriate for your disease case.