Thirty-three states and the District of Columbia currently have medical marijuana programs. Half—California, Connecticut, Florida, Georgia, Illinois, Iowa, Massachusetts, Missouri, New Hampshire, New Mexico, New York, Ohio, Oklahoma, Pennsylvania, South Carolina, Vermont, and West Virginia—have listed Parkinson’s Disease as a qualifying condition.
In May, the Parkinson’s Foundation issued a bulletin, Consensus Statement on the Use of Medical Cannabis for Parkinson’s Disease, to serve as guidance for physicians and their patients. The top takeaways from their findings were:
Our experts urge caution: there are adverse effects, toxicity issues, and drug to drug interactions, and we don’t fully know what this means for people with PD who are taking PD medications.
Given the lack of any clear data supporting the use of cannabis in PD, the Foundation does not endorse their use for PD symptoms or to modify disease progression. However, because we realize that people with PD are interested in trying cannabis products, we are providing guidance for both general safety as well as working with dispensaries.
Some studies have suggested cannabis may be beneficial for non-motor symptoms such as sleep disturbances, pain, anxiety, and gastrointestinal issues. However, these studies are generally small, uncontrolled (meaning there is no placebo comparison, which increases the risk of false positive results), and are open label (meaning both the health providers and patients are aware of the drug or treatment being given, which could influence the results). More rigorous research is needed to determine if there is any medical benefit.
Additionally, there is still only limited evidence to suggest that cannabis is beneficial for the treatment of levodopa-induced dyskinesias, though a larger body of evidence indicates that cannabis is effective at reducing tremors or tics. More research will be needed to determine if this is true and, if so, to what extent.
There is far more evidence to support the claim that cannabis is effective at treating non-motor symptoms, including:
Loss of appetite
It is also important to note that the use of THC-rich formulations may negatively impact decision-making capacity, balance, and anxiety. It could also further reduce blood pressure. Products containing CBD only or a relatively low concentration of THC (20:1 CBD:THC) may be more suitable for patients hoping to treat symptoms such as sleep disturbance, pain, or anxiety.
To read the Foundation’s Consensus Statement on the Use of Medical Cannabis for Parkinson’s Disease in full, click here.