Cannabis in Parkinson's Disease: The Patients' View

BACKGROUND: Little is known about the patients' view on treatment with medical cannabis (MC) for Parkinson's disease (PD).

OBJECTIVE: To assess the PD community's perception of MC and patients' experience with MC.

METHODS: Applying a questionnaire-based survey, we evaluated general knowledge and interest in MC as well as the frequency, modalities, efficacy, and tolerability of application. Questionnaires were distributed nationwide via the membership journal of the German Parkinson Association and locally in our clinic to control for report bias.

RESULTS: Overall, 1.348 questionnaires (1.123 nationwide, 225 local) were analysed. 51% of participants were aware of the legality of MC application, 28% of various routes of administration (ROA) and 9% of the difference between delta9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). PD-related cannabis use was reported by 8.4% of patients and associated with younger age, living in large cities and better knowledge about the legal and clinical aspects of MC. Reduction of pain and muscle cramps was reported by more than 40% of cannabis users. Stiffness/akinesia, freezing, tremor, depression, anxiety and restless legs syndrome subjectively improved for more than 20% and overall tolerability was good. Improvement of symptoms was reported by 54% of users applying oral CBD and 68% inhaling THC-containing cannabis. Compared to CBD intake, inhalation of THC was more frequently reported to reduce akinesia and stiffness (50.0% vs. 35.4%; p <  0.05). Interest in using MC was reported by 65% of non-users.

CONCLUSION: MC is considered as a therapeutic option by many PD patients. Nevertheless, efficacy and different ROA should further be investigated.