Increased demand for cannabis among Parkinson’s patients

A recent research paper from Germany adds to a growing evidence base suggesting that cannabis could be an effective treatment for Parkinson’s Disease. Cannabis Health speaks to the lead investigator of the study, Professor Carsten Buhmann.

A survey of Parkinson’s disease patients in Germany, conducted by scientists at the University Medical Centre Hamburg-Eppendorf, found that more than half reported a beneficial clinical effect of cannabis products on their symptoms.

Since 2017, cannabis prescriptions for those with severe Parkinson’s disease have been legal in Germany.

A debilitating illness that affects around 10 million people worldwide*, Parkinson’s affects nerve cells responsible for the release of dopamine deep inside the brain.

Those with the disease progressively lose these neurons, developing degenerative symptoms such as tremors, slow movement, stiff muscles and various psychological conditions.

Past research has found that cannabis and cannabinoids could have an impact on the affected area of the brain known as the dopaminergic system.

Adding to this growing body of evidence, the recent study from lead author and doctoral student, Ferhat Yenilmez, demonstrates the potential of cannabis for treating Parkinson’s disease, revealing that 54 percent of patients reported clinical benefits.

Of the 1,300 patients involved in the study, more than eight percent said that they used cannabis-based products to relieve their symptoms.

Forty percent reported that cannabis helped ease pain or cramps, whilst 20 percent said it helped with stiffness.

A further 20 percent of cannabis users with symptoms of freezing, tremor, depression, anxiety or restless legs also reported a clinical benefit.

The majority of patients reported using CBD, with 39.8 percent saying that they used the non-psychoactive cannabinoid for relieving their symptoms. Products including THC were less popular but only by around 10 percent.

Of the 113 participants who said they consumed cannabis, 9.7 percent reported that they used THC and 17.7 percent reported using a combination of CBD and THC (30.1 percent in total).

Whether those who used THC did so through a prescription or through the illicit market is unknown, as researchers feared that asking the question could deter patients from taking part in the survey.

Interestingly, 17.7 percent reported that they were not aware of which substance they used, indicating that knowledge of cannabis-based medicines is low amongst those who use cannabis to treat their symptoms.

“Our data confirm that PD patients have a high interest in treatment with medicinal cannabis but lacked knowledge about how to take it and especially the differences between the two main cannabinoids, THC and CBD,” says Professor Carsten Buhmann of the University Medical Centre Hamburg-Eppendorf.

“Epidemiological factors and increasing media attention suggest that interest in cannabis will increase significantly in the next few years. For this reason, it is of great importance to educate patients about the medical uses of cannabis.”

Buhmann asserts, however, that increased public awareness should not be the main goal, rather increased clinical data is needed to improve the medical cannabis landscape.

“It should be pointed out that there is still a lack of sufficient study data regarding efficacy and tolerability of medical cannabis applied in Parkinson’s disease,” Buhmann explains.

“Meaningful areas of application should first be identified and randomised controlled studies need to be done.”

In Germany, cannabis-based medicinal products are available to patients with severe and quality of life-impairing symptoms, but only if previous therapies were unsuccessful or poorly tolerated.

According to Buhmann, this is the first time that the country has approved a substance without a specific indication and without any standard study demonstrating its efficacy or safety.

Putting this down to political reasons, Buhmann says the unprecedented change to cannabis’ legal status has led to a number of issues in the healthcare system.

“There is an intense demand from patients with Parkinson’s Disease for treatment with cannabinoids, which is supported by the broad media interest and spectacular case reports on internet platforms showing tremendous improvement of  symptoms such as dyskinesia or tremor after application of marijuana,” he says.

“However, health insurances more and more [refuse] to reimburse the expensive treatment with cannabis and argue that the conditions for prescription are not fulfilled. This leads to increasing social judicial disputes.

“As a legislator, one could and should have considered this before allowing a substance without reliable studies.”

Buhmann believes that, as evidence is still lacking, medical professionals need to be responsible for explaining the gap in evidence to their patients and should be aware that many might have already used cannabis without a medical prescription.

Despite the promising results from his study, Buhmann is reluctant to offer a general recommendation to the medical community until further investigations take place into the efficacy and tolerability of medical cannabis and its various routes of administration.

However, he hopes that the study can be used by both doctors and patients to help them in deciding whether a cannabis prescription is right for each individual case.

“Physicians should consider these aspects when advising their patients about treatment with medicinal cannabis,” Buhmann adds.

“The data reported here may help physicians decide which patients could benefit, which symptoms could be addressed, and which type of cannabinoid and route of administration might be suitable.

“Especially in later stages of the disease, a co-medication with medical cannabis might be justified because, at that point, some symptoms are often not optimally treatable or not treatable at all.”

Moving forward, the team of scientists say they are looking to take part in a multi-centre prospective study and controlled study in order to continue building the scientific data surrounding Parkinson’s disease and its possible treatment using medical cannabis.

*European Parkinson’s Disease Association