Parkinson’s disease is a long-term progressive disorder of the nervous system that affects the body’s motor system. The degenerative disease causes the death of neurons that produce dopamine, a chemical that sends messages to the part of the brain that controls movement and coordination. Symptoms of Parkinson’s disease often begin with a tremor in one hand and gradually develop into shaking, rigidity, postural instability, dyskinesia, and slowness of movement. Psychosis can also occur, and in advanced stages of the disease, dementia often develops.
In the study, the researchers, headed up by Mario Stampanoni Bassi of the Department of Systems Medicine at Rome’s Tor Vergata University, examined the available preclinical and clinical studies involving cannabinoid-based therapies in Parkinson’s disease.
They found that cannabinoids and their interaction with the endocannabinoid system, a system that regulates several body processes, has shown beneficial for symptoms of Parkinson’s disease. Cannabis’ interaction with the endocannabinoid system’s cannabinoid receptors, CB1 and CB2, modulates the release of the neurotransmitter dopamine. The interaction with the CB1 and CB2 receptors has shown in several preclinical studies to improve motor impairment. Two surveys of Parkinson’s disease patients found smoking marijuana to be beneficial for tremor, rigidity, bradykinesia, pain, and sleep symptoms. A questionnaire found the cannabinoid cannabidiol (CBD) to reportedly help with psychosis in Parkinson’s disease.
The researchers did note that results from the limited available clinical studies examining cannabis’ effects on Parkinson’s disease have been inconclusive because of small sample sizes, expectancy bias, and a lack of standardized outcome. Stampononi Bassi and his team urged for more clinical studies.
“Despite the low sample size and quality of these studies, the data suggest that some motor symptoms in [Parkinson’s disease], in particular [levodopa-induced dyskinesias], may respond to cannabis-based therapies,” the researchers wrote in their study.
“Well-designed studies involving larger sample of patients, appropriate molecular targets, objective biological measures (i.e. CBs blood level), and specific clinical outcome measures are needed to clarify the effectiveness of [cannabinoid]-based therapies,” the researchers added.
In December, Dr. Stuart Titus, the CEO of Medical Marijuana, Inc., was interviewed by UOL News in Brazil about the effects of cannabis, specifically CBD, on Parkinson’s disease. AXIM Biotechnologies, Medical Marijuana, Inc.’s investment company, is currently in the midst of developing cannabinoid-based pharmaceuticals and treatments for several conditions with no known effective treatments, including Parkinson’s disease.