Can Medical Cannabis Help Treat Parkinson’s Disease?

The expanding legalization of medical cannabis globally has triggered the interest of medical researchers to test the plant’s compounds on various diseases. One of them is Parkinson’s disease (PD) - the progressive nervous system disorder that could lead to mobility impairment.  A study of PD patients in Germany, recently published in the Journal of Parkinson’s Disease, showed that over 8% of patients with the disease report using cannabis products in their treatment. Over half of those users (54%) said they had improvements from taking medical cannabis.  There are some criteria users must fulfill in Germany before they can use cannabis to treat progressive and - in the last stages - debilitating conditions like Parkinson’s. For example, they can try out if medical cannabis works for them when they show resistance to regular therapy.  The data is scarce about which type of cannabinoid and which route of intake would work the best for PD patients. The recent research aimed to answer some of these gaps in data.  In 2019, researchers moved to assess patient perceptions of medicinal pot and evaluate patients' experiences already using related products.  As part of the research, a questionnaire was sent to the members of the German Parkinson Association (Deutsche Parkinson Vereinigung e. V.), which has almost 21,000 members within several German-speaking countries.  Over 1,300 individuals filled in the questionnaire, revealing that the PD community has a high interest in medical cannabis, however, their knowledge of the different types of products was limited. For instance, only 28% of respondents were aware that cannabis has different administration routes despite inhaling. Less than 10% knew the difference between THC and CBD, the primary psychoactive and non-psychoactive chemicals found in the plant.  Correspondents appeared more informed on the legality of cannabis, with 51% nodding positively they are aware of legality aspects, however. 

To cut to the most significant part of the study, over 8% of patients responding to the questions answered that they are using medical cannabis, and 54% of those reported they had a beneficial effect from the intake. More than 40% of users reported that it helped manage pain and muscle cramps. Over 20% of users said it offered relief from stiffness or akinesia, the loss of voluntary movement in PD patients. It also helped them with freezing, tremor, restless leg syndrome, and mental health issues like anxiety and depression. Between THC and CBD products, patients said inhaling THC was the most efficient way to offer relief from stiffness. CBD products were found to be, perhaps surprisingly, less well tolerated. The study participants' background and age also appeared to be important, with those more aware of the legal and clinical aspects of medicinal cannabis having been identified to come from larger cities and be of younger age.  Between non-users, as much as 65% of respondents said they had an interest in trying medicinal cannabis but cited lack of knowledge and fear of side effects as the main reasons for avoiding trying it. “These findings are interesting in that they confirm a widespread interest among patients in the use of cannabis as a potential treatment for people living with PD,” said Bastiaan R. Bloem, MD, expert research in Parkinson’s and the Co-Editor in Chief of the Journal of Parkinson’s Disease.  “It is important to emphasize that more research is needed before cannabis can be prescribed as a treatment and that guidelines currently recommend against the use of cannabis, even as self-medication, because the efficacy is not well established, and because there are safety concerns (adverse effects include among others sedation and hallucinations). As such, the present paper mainly serves to emphasize the need for carefully controlled clinical trials to further establish both the efficacy and safety of cannabis treatment," Bloem said. 

The American Parkinson’s foundation also notes on its website that “studies [in general] have not clearly supported the use of marijuana for PD.” “While some [study] results have been positive, the effects of medical marijuana are probably not completely understood, which is why more studies, especially those with more subjects, are needed,” the website reads. If more trials come up and medical research finds a way to treat this neurodegenerative condition, it could help about 60,000 Americans diagnosed with PD every year and hundreds of thousands other worldwide. 

What conditions can medical cannabis help for?

Some of the most common health conditions physicians prescribe medical cannabis to patients is to treat chronic pain, anorexia and appetite loss (often due to cancer treatment or due to HIV/AIDS), epilepsy (especially rare forms like Dravet syndrome), and mental health conditions like PTSD, depression, and anxiety. Medical cannabis can be considered as a form of treatment for an array of other diseases like Alzheimer’s, Crohn’s disease, Multiple Sclerosis (MS), and Wasting syndrome, to name a few. Medical cannabis is in a clinical trial for various other diseases, and its promise to the medical community has been tremendous. The issue of the legality of cannabis has undermined medical research in the U.S., however. Foreign countries like the Netherlands, Israel, and Canada are some of the world leaders in terms of medical research. Cannabis drugs can contain THC (tetrahydrocannabinol, the primary psychoactive compound of cannabis) and/or CBD (pure cannabidiol, derived from hemp), which is becoming more widely available across pharmacies around the world.