The use of cannabidiol (CBD) in the treatment of Parkinson’s disease and its comorbidities

Abstract

Background: Parkinson’s disease (PD) is a chronic neurodegenerative disorder characterized by motor (bradykinesia, tremors, stiffness) and non-motor (psychotic, mood and sleep disorders) symptoms. The available pharmacological treatments are not effective for a significant portion of the patients. Recent research suggests that the phytocannabinoid cannabidiol (CBD) could be effective in treating some PD symptoms. Objectives: To review the preclinical and clinical studies of the effects of CBD on the symptoms of PD. Methods: Narrative review of the main basic and clinical studies on the effects of CBD on the symptoms of PD. Due to the small number of clinical studies, research with other cannabinoids was also included. Results: A total of 15 articles were included in the review: 5 preclinical studies involving the administration of CBD and 10 studies with patients involving the administration of different cannabinoids (cannabis, nabilone, CBD). Most of the basic studies reported a positive effect of CBD on PD-related behavior or biochemical changes. Observational and clinical studies using smoked cannabis, oral cannabis extract, nabilone (synthetic cannabinoid) and CBD suggest that these cannabinoids can reduce motor (bradykinesia, tremors, stiffness) and non-motor (psychotic, mood and sleep disorders, quality of life) symptoms of PD. Moreover, they are well tolerated substances with few significant adverse effects. Conclusion: Although CBD has shown favorable results in both preclinical and clinical studies, this evidence is not yet sufficient to indicate the use of this cannabinoid in patients with PD. New controlled studies should be performed with different dosages of CBD to replicate this data.