Trial to Test CBD for Parkinson’s-Related Psychosis

Cannabis plant (Michael Fischer, Pexels.com)

14 Oct. 2019. A clinical trial is planned to test cannabidiol, or CBD, derived from cannabis as a treatment for hallucinations and delusions among people with Parkinson’s disease. The trial will be conducted by the charitable and advocacy group Parkinson’s UK with researchers at Kings College London.

Parkinson’s disease occurs when the brain produces less of the substance dopamine, a neurotransmitter that sends signals from one neuron or nerve cell to another. As the level of dopamine lowers, people with Parkinson’s disease become less able to control their bodily movements and emotions. Symptoms include tremors, i.e. shaking, slowness and rigidity in movements, loss of facial expression, decreased ability to control blinking and swallowing, and in some cases, depression, or psychosis. According to the Parkinson’s Disease Foundation, more than 10 million people worldwide are living with the disease.

Parkinson’s UK says some 145,000 people in the U.K. are living with Parkinson’s disease, and half or more experience symptoms of psychosis, such as hallucinations or delusions. The group says no treatment is currently approved in the U.K. for this condition, thus the interest in cannabidiol. While derived from cannabis, cannabidiol does not produce an emotional high associated with marijuana, and is missing tetrahydrocannabinol or THC, the psychoactive component of marijuana causing intoxication.

Authorities in the U.S. and Europe approved treatments for some forms of childhood epilepsy containing cannabidiol, for its ability to reduces hyperactivity of neurons by limiting chemical stimuli and signals associated with seizures. Sagnik Bhattacharyya, a professor of neuroscience and psychiatry at Kings College London studies cannabidiol’s potential as a treatment for psychosis, including clinical trials. Parkinson’s UK asked Bhattacharyya and Kings College colleague Latha Velayudhan to lead the trial in patients with Parkinson’s disease.

The clinical trial has two parts. The first part is a small-scale test seeking to find an optimum dose of cannabidiol, up to 1,000 milligrams, expected to take six weeks. The main part of the study is recruiting 120 individuals with Parkinson’s disease and also experiencing psychosis. This 12-week study will test effects of cannabidiol, with participants randomly assigned to received cannabidiol or a placebo.

Earlier in 2019, Parkinson’s UK conducted a survey of people with Parkinson’s disease and health care professionals on their attitudes toward potential cannabis-related treatments. About a quarter of respondents with Parkinson’s disease (26%) say they currently or previously used cannabis-related treatments, and another six in 10 (59%) say they have not used cannabis-derived treatments, but would consider using them for their symptoms if available. Large majorities of professionals surveyed say patients ask about cannabis-related treatments, but are reluctant to advise patients because of the lack of solid evidence on their effectiveness.

“There are many unanswered questions about the value of CBD for people with Parkinson’s,” says Arthur Roach, director of research at Parkinson’s UK in an organization statement, “but this trial will help us to determine whether it can help with the debilitating symptoms of hallucinations and delusions. If successful, this trial could result in people with Parkinson’s being able to access a regulated medicine, rather than reverting to expensive unregulated supplements that haven’t been monitored for their effectiveness.”

More from Science & Enterprise:

• Sensors, Algorithm Personalize Parkinson’s Therapy
• Fox Foundation Supports Parkinson’s Walking Device
• RNA Therapy Studied for Parkinson’s Side Effects
• FDA Clears Inhaled Parkinson’s Drug
• Biotech, Institute Partner on Gut Microbe Links to Parkinson’s

*     *     *