Medical Marijuana With medical marijuana now legalized in 38 states and the District of Columbia, there is strong interest in its therapeutic properties. Researchers are testing marijuana, which The benefits and research around using CBD and medical marijuana to help treat the symptoms associated with Parkinson’s disease.
With medical marijuana now legalized in 38 states and the District of Columbia, there is strong interest in its therapeutic properties. Researchers are testing marijuana, which is also called cannabis, as a treatment for many illnesses and diseases, including Parkinson’s disease (PD). However, despite this interest, there isn’t conclusive scientific evidence that marijuana is beneficial in PD.
The Science Behind Marijuana
What is the science and pharmacology behind marijuana, and can it be used to treat Parkinson’s symptoms?
The endocannabinoid system is located in the brain and made up of the endocannabinoids (molecules in our body that act on the cannabinoid receptors) and cannabinoid receptors (a molecular switch on the outside of a cell that makes something happen inside a cell when activated) on neurons (brain cells). The endocannabinoid system helps regulate many functions, including memory, pleasure, concentration, movement, appetite, and pain.
Researchers began to show enthusiasm to study cannabis in relation to PD after people with PD gave anecdotal reports and posted on social media as to how cannabis allegedly reduced their tremors. Some researchers think that cannabis might be neuroprotective (ie, that it saves neurons from damage caused by PD), though there have not yet been studies in humans that demonstrate this effect.
Cannabinoids (the drug molecules in marijuana) have also been studied for use in treating other symptoms, like bradykinesia (slowness caused by PD) and dyskinesia (excess movement caused by levodopa). Despite some promising preclinical findings, researchers have not found any meaningful or conclusive benefits of cannabis for people with PD.
The Pharmacology of Cannabis
The two primary components (ie, cannabinoids) of marijuana are delta-9-tetrahydrocannibinol (THC) and cannabidiol (CBD). THC and CBD act on the cannabinoid receptors type 1 (CB1) and type 2 (CB2), which are primarily found throughout the nervous system and on cells of the immune system. The way that THC and CBD acts on these two receptors is different and may help explain the different effects mediated by each of these compounds. For example, THC is the psychoactive component of marijuana and causes alterations in perception and mood. CBD, on the other hand, can reduce anxiety and may have anti-inflammatory properties.
The various compounds present in different marijuana plants and their variable effects on the CB1 and CB2 receptors make cannabis studies difficult to conduct. When researchers study the effects of a medication, dosages are controlled and often set to a specific number of milligrams. When testing medical marijuana, the dosage administered can vary dramatically depending on the plant and method of administration.
PD-Related Medicinal Marijuana Trials
The use of cannabinoids has been suggested to help with managing neurological and non-neurological conditions. Literature on medical marijuana is incredibly varied. Studies have not clearly supported the use of marijuana for PD. The clinical studies of cannabis as a PD treatment that have been conducted are generally small studies that are predisposed to biases. Most of studies have not followed the clinical trial gold standard of a double blind, placebo-controlled trial design. Some studies had as few as five subjects.
While some results have been positive, the effects of medical marijuana are probably not completely understood. This is why more studies, especially those with more subjects, are needed.
PD-related Medical Marijuana Studies
Clinical observations and trials of cannabinoid-based therapies suggest a possible benefit to tics and probably no benefit for tremor in dyskinesias or PD motor symptoms. Further preclinical and clinical research is needed to better characterize the pharmacological, physiological and therapeutic effects of this class of drugs in movement disorders.
The authors demonstrate that nabilone, the cannabinoid receptor agonist, significantly reduces levodopa-induced dyskinesia in PD.
This study is an evaluation of the effects of three antagonists on the NK3, neurotensin and cannabinoid receptors on the severity of motor symptoms and levodopa-induced dyskinesias after administration of a single dose of levodopa in 24 people with PD. The study concluded that the drugs tested were safe, but did not improve Parkinsonian motor disability.
This study reviews the endocannabinoid system and its regulatory functions in health and disease.
Risks and Benefits for People with PD
There are risks and benefits associated with the use of cannabis for people with PD. Benefits include a possible improvement in anxiety, pain, sleep dysfunction, weight loss and nausea. Potential adverse effects include impaired cognition (specifically in executive function, or planning and judgement), dizziness, blurred vision, mood and behavioral changes, loss of balance and hallucinations. Chronic use of marijuana can increase the risk of mood disorders, particularly among young users, and lung cancer.
Researchers issue caution for people with PD who use cannabis particularly because of its effect on thinking. PD can impair the executive function — the ability to make plans and limit risky behavior. People with a medical condition that impairs executive function should be cautious about using any medication that can compound this effect.
Medical Marijuana and Legislation by State
Thirty-eight states and Washington, DC have passed legislation allowing the use of marijuana-based products as a medical intervention.
In some states where medical marijuana is legalized, consumers must register to possess and use cannabis. Other states require consumers to acquire a document from a physician stating that the person has an approved condition. Under federal law doctors cannot prescribe cannabis, but many states authorize them to issue certifications that allow people to obtain medical marijuana.
PD is listed as a qualifying condition for medical marijuana in California, Connecticut, Florida, Hawaii, Illinois, Louisiana, Maine, Massachusetts, Michigan, Mississippi, Missouri, New Hampshire, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, Vermont and West Virginia.
Medical marijuana is legal in Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Hawaii, Illinois, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Dakota, Utah, Vermont, Virginia, Washington, West Virginia and Washington, DC.
Eighteen states and the District of Columbia have legalized the recreational use of marijuana, making it legal for adults over the age of 21 to legally consume marijuana without a doctor’s recommendation. Many of these states still differentiate recreational from medical marijuana. In some states, medical marijuana consumers may have access to specialized dispensaries, strains of marijuana and sales tax exemptions.
Recreational marijuana is legal in Alaska, Arizona, Connecticut, California, Colorado, Illinois, Maine, Massachusetts, Michigan, Montana, New Jersey, New Mexico, New York, Nevada, Oregon, Virginia, Vermont, Washington and Washington, DC.
Multiple states, counties or cities have decriminalized certain marijuana-related offenses. In these areas, the possession of marijuana can be met with a citation — forgoing an arrest or criminal record — or no penalty at all.
For state-by-state guidance on marijuana legalization, medical laws and discrimination visit Norml.org/laws.
Parkinson’s Foundation Centers of Excellence and Medicinal Marijuana
The Parkinson’s Foundation, in partnership with Northwestern University researchers, studied attitudes about cannabis at 40 Centers of Excellence — members of our Global Care Network. To the best of our knowledge, this is the first study to provide data on the practices, beliefs and attitudes of expert PD physicians concerning cannabis use.
The results were interesting: most experts said they knew what cannabis did but disagreed on the details. While there is no general agreement on what the benefits might be for people with PD, the survey confirmed that cannabis is a popular subject within Parkinson’s Foundation centers, as 95 percent of neurologists reported people have asked them to prescribe it.
These cannabis study results also included:
- Only 23% of physicians had any formal education on the subject of cannabis (such as a course or lecture), thus 93% of physicians want cannabis taught in medical school.
- Physicians reported that 80% of their people with PD have used cannabis.
- Only 10% of physicians have recommended the use of cannabis to people with PD.
- In terms of memory: 75% of physicians felt that cannabis would have negative effects on short-term memory and 55% felt that cannabis could have negative effects on long-term memory.
- Only 11% of physicians have recommended use of cannabis in the last year.
This graph shows how physicians expect cannabis would improve, worsen or show no effect to PD-related symptoms given their expertise and observations of people with PD.
The study emphasized that physicians would be more apt to use medical marijuana as a treatment if it was approved through regulation instead of legislation. Nearly all medications are only approved after passing a science-based evaluation proving their effectiveness in a process overseen by the Food and Drug Administration. Since cannabis has been approved through legislation rather than regulation, there are no labels, dosage recommendations or timing instructions that physicians can reference.
Is medical marijuana an option for me?
What’s next for a person with PD who wants to know if medical marijuana is an option? “Marijuana should never be thought of as a replacement for dopaminergic and other approved therapies for PD,” said Dr. Michael S. Okun, the Parkinson’s Foundation National Medical Advisor.
Research is still needed to determine how medical marijuana should be administered and how its long-term use can affect symptoms of PD. To keep people safe, states that legalize medical marijuana will eventually need to develop training programs for doctors and medical teams that prescribe medical marijuana. Consult your doctor to see if medical marijuana is an option for you.
The Parkinson’s Foundation Consensus Statement on the Use of Medical Cannabis for Parkinson’s Disease is designed to help guide the PD community in making informed decisions about using cannabis for Parkinson’s. The statement is based on the input from 46 experts who attended the Foundation’s first-ever medical marijuana convening. Read it now.
Page reviewed by Dr. Chauncey Spears, Clinical Assistant Professor and Dr. Sydney M. Spagna, Clinical Fellow at the University of Michigan.
Using CBD to Treat Parkinson’s Disease Symptoms
The benefits and research around CBD are still emerging
Colleen Travers writes about health, fitness, travel, parenting, and women’s lifestyle for various publications and brands.
Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more.
Diana Apetauerova, MD, is board-certified in neurology with a subspecialty in movement disorders. She is an associate clinical professor of neurology at Tufts School of Medicine.
With the legalization of medical marijuana, many states are approving the use of it in a non-traditional way to treat the symptoms of certain conditions, including Parkinson’s disease. Marijuana has two major components to it—tetrahydrocannabinol (THC) and cannabidiol (CBD). Both may help with nausea and muscle pain or spasms, but unlike THC, CBD doesn’t give you the “high” feeling marijuana is most commonly known for. This makes it an enticing, natural way for many to help treat their Parkinson’s disease symptoms. What’s more, is that because CBD is a natural compound from the Cannabis sativa plant, using it may also leave you side effect-free, unlike many prescription medications.
The body of research on using CBD for Parkinson’s disease symptoms is rapidly growing, as Parkinson’s disease affects 1% of the population over 60 years old. Parkinson’s disease is a neurological condition, affecting the nervous system. Parts of the brain that produce dopamine, which is responsible for sending messages to the body in order to direct movement, become damaged or die. This results in tremors, muscle stiffness, the inability to use facial expressions, and trouble balancing.
In connection with Parkinson’s disease as well as other movement-related disorders, CBD may help improve motor skills. In one study published in Frontiers in Pharmacology CBD was shown to have a more preventative role in delaying abnormal movement symptoms in animal models of Parkinson’s.
Since Parkinson’s disease can take some time to properly diagnose when the symptoms are already prevalent, using CBD once diagnosed may not offer much benefit. With early detection combined with the use of CBD together the possibility of reducing movement-related symptoms increases.
Those dealing with Parkinson’s disease may also have trouble sleeping due to REM sleep behavior disorder (RBD), a condition in which patients ‘act out’ their dreams while asleep. A study published in the Journal of Clinical Pharmacy and Therapeutics found that four patients with Parkinson’s disease who also suffered from RBD had a decrease of RBD symptoms during sleep with the use of CBD.
In some cases, people suffering from Parkinson’s disease may also have symptoms of psychosis, ranging in hallucinations to vivid dreams and illusions. Research has found that CBD may be able to help. In research out of University of São Paulo in Brazil, patients were given a dose of CBD starting out at 150 milligrams (mg) per day in addition to their current treatment plan of therapy for four weeks. The use of CBD showed no adverse effects, no impact on worsening motor function, and a decrease in their reported psychosis symptoms, meaning that not only can it help with the physical setbacks of Parkinson’s disease, it can also play a part in the cognitive challenges as well. This was however an older study and current clinical trial evidence to support the use of CBD is minimal.
More research out of Brazil suggests CBD can improve the overall quality of life of those with Parkinson’s disease. In a sample of 21 patients, those who were treated with 75 mg to 300 mg of CBD per day reported a significant increase in quality of life, though no significant differences were noted in motor and general symptoms or neuroprotective effects. This goes to show how much results can vary when it comes to the effects of CBD, requiring larger studies to be done in order to get more definitive answers to this treatment option.
Uses and Safety
Parkinson’s disease can impact cognitive function and memory, particularly in those whose symptoms progress to Parkinson’s disease dementia. Because of this, medical marijuana with both THC and CBD may not be recommended, as it can impair thinking and brain function even more so. CBD by itself may be a safer route.
CBD has been discovered as an effective way to help treat Parkinson’s disease symptoms because it interacts with two cannabinoid receptors in the body found on certain cells called CB1 and CB2. By interacting with one or both of these receptors, CBD may delay tremor development as well as have protective neurological benefits. But as seen with the above studies, there is no uniform approach or conclusion on this treatment method. This means that patients may react differently to using CBD, some having tremendous success while others seeing little difference. But regardless of whether or not CBD is an effective treatment option for you, you always need to consult your treating physician to make sure this treatment will not cause side effects.
What can cause side effects is if a patient decides to mix medical marijuana with their treatment plan that consists of certain prescription medications. If you plan to use medical marijuana as opposed to CBD by itself, it’s smart to consult a healthcare provider or your pharmacist before you start mixing it in with other medications to make sure it’s safe for you.
Should You Use It?
While the research on CBD to treat Parkinson’s disease symptoms is largely inconclusive, its mild effect on patients as a whole makes it enticing to try in addition to an existing traditional treatment plan. Parkinson’s disease has no cure. But with prescription medication, therapy, and now perhaps the use of nontraditional options like CBD, patients may be able to experience less frequency and severity of symptoms that affect their motor skills.
If you’re interested in trying CBD for Parkinson’s disease, talk to your healthcare provider about it. They will be able to point you to the latest research and provide recommendations on how much you should take. They will also be able to monitor your progress with the rest of your care team in order to come to a conclusion if this is the right treatment plan for you.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Peres FF, Lima AC, Hallak JEC, Crippa JA, Silva RH, Abílio VC. Cannabidiol as a Promising Strategy to Treat and Prevent Movement Disorders?. Front Pharmacol. 2018;9:482. doi:10.3389/fphar.2018.00482
Davis Phinney Foundation for Parkinson’s website. New Research, Medications, and CBD for Parkinson’s. Updated November 14, 2018.
Parkinson’s Foundation website. Medical Marijuana.
The Michael J. Fox Foundation for Parkinson’s Research website. Ask the MD: Medical Marijuana and Parkinson’s Disease. Update May 2, 2018.