April is Parkinson’s Disease Awareness Month. According to the Parkinson’s Foundation, there are more than one million people living with the disease in the US alone. In addition, reports from Blue Cross Blue Shield indicate that prevalence rates of the disease are increasing, perhaps by more than 50 percent over a five-year period.
As of 2022, several clinical trials have investigated the safety, efficacy, and tolerability of cannabis, specific phytocannabinoids, and synthetic cannabinoids for the treatment of Parkinson’s and its symptoms.
With a more substantial scientific basis than ever before, what do we really know about medical cannabis for the relief for the anxiety, pain, insomnia, and motor effects associated with this neurodegenerative disorder? Is it time to take this alternative approach seriously?
What We Know About Medical Cannabis for Parkinson’s Disease
Like all areas of medical cannabis research, years of anti-cannabis rhetoric and funding challenges hampered the study of cannabis for Parkinson’s disease.
Yet today, a majority of American states have legal, medical cannabis programs. Not to mention that federal regulatory changes are looming. As a result, it’s now easier for researchers to study cannabis and for patients to access it.
Do people with this disease already rely on cannabis to relieve symptoms? A survey on cannabis use among people living with Parkinson’s disease in the US published in 2021 sought to find out.
With more than 1,000 respondents, the authors discovered that 24.5 percent of respondents had used cannabis in the last six months. Of those who used medical cannabis, the majority did so strictly to relieve their Parkinson’s symptoms. Approximately 45 percent used it to calm anxieties, 44 percent to treat pain, and 44 percent for sleep issues.
If a quarter of people with Parkinson’s may already be dabbling with medical cannabis for symptom relief, is there any scientific support for their approach?
In 2022, the Journal of Cannabis Research published “Cannabinoids in the management of behavioral, psychological, and motor symptoms of neurocognitive disorders,” a systematic review. The authors included 11 studies in their final review.
Excitingly, based on this analysis, cannabis-based medicines seem to improve non-motor symptoms (falls, depression, pain, and sleep disturbances).
This systemic report found ‘good’ and ‘fair’ evidence that pharmaceutical cannabinoids are effective “in relief from agitation in the context of dementia” relevant to Parkinson’s disease. It’s a strong foundation of evidence. Now, combined with the number of patients already seeking alternatives, we need more robust, placebo-controlled studies.
Medical Cannabis for Parkinson’s: Past, Present, and Future of Clinical Trials
In a ClinicalTrials.gov search, approximately ten trials were on record for cannabis and the treatment of Parkinson’s. At the time of writing, two of these had results. However, both trials were small, working with 10 and 13 participants, respectively. The first tested Nabilone and the latter cannabidiol (CBD).
Digging into one of these studies, “Safety and Tolerability of Cannabidiol in Parkinson Disease: An Open Label, Dose-Escalation Study,” published in 2020, there are two important discoveries. The first takeaway is that participants experienced measurable improvements in motor movements (tremors) and nighttime sleep, alongside emotional and behavioral improvements.
The second critical finding is that the high doses required during this study led to notable adverse effects. Although mild, the majority of patients experienced diarrhea (85 percent), somnolence (69 percent), and fatigue (62 percent). In addition, researchers measured elevated liver enzyme levels.
The conclusion? The team stated, “CBD, in the form of Epidiolex, may be efficacious in PD, but the relatively high dose used in this study was associated with liver enzyme elevations.” More study is needed to explore this further. Future studies could explore larger sample groups, comparison against conventional treatments, delivery in conjunction with conventional treatments, or testing other cannabis formulations.
Parkinson’s Disease Needs More Study, Including the Efficacy of Cannabis
Like much of the medical cannabis world, people with Parkinson’s who would like to explore this plant-based therapy option are stuck in a strange state of limbo.
On the one hand, most states in the US have now approved medical cannabis as a viable treatment option — at least to some degree — while on the other, federal regulation is lagging. With federal legislation preventing or slowing robust clinical research until recently, where do patients turn when they want more information? It turns out it’s rarely to their physician.
Of the 1,000 plus respondents to the 2021 survey highlighted above, many reported getting their information from friends, family, or the media. What’s more, most people who used cannabis did not do so through the recommendation of a doctor, even if they lived in a state with medical cannabis.
As per the authors, “Our results suggest that the lack of formal guidance or research evidence about cannabis for [Parkinson’s Disease] may in part underlie inconsistencies in both use and reported effectiveness.”
With several larger clinical trials scheduled for the near future and changes to how the federal government manages cannabis research, these discrepancies may be set to change. Given these changes, it’s not unreasonable to expect that medical cannabis will likely enter into the realm of possibility for Parkinson’s disease. It soon may be on the table as a legitimate tool for symptom control.