Tourette syndrome (commonly known as Tourette’s) is a neuropsychiatric disorder characterized by the presence of multiple motor and one or more vocal tics that continue for at least one year. Tics range from mild to severe, where severe symptoms can significantly interfere with communication, daily functioning and quality of life.
Current treatments for Tourette’s include behavioural therapy, and medications such as antipsychotics and Alpha-2-receptor agonists. However, these medicines have to potential to cause severe side effects and other treatments have limited evidence.
Recently, a retrospective study was performed to evaluate the effectiveness and tolerability of cannabis treatment in adult patients with Tourette’s. Nineteen patients using cannabis for Tourette’s at the Tourette Syndrome Neurodevelopmental Clinic in Toronto, Ontario were identified and interviewed using standardized questionnaires for tic severity, ADHD, OCD, DSM-IV Axis I Disorder, and the Marijuana Effect Expectancy Questionnaire (MEEQ). Assessment for adverse effects associated with cannabis was based on open-ended questions, as well as the SCID-I/P psychosis interview and the MEEQ. Finally, clinicians completed the Clinical Global Impressions Improvement (CGI-I) and Clinical Global Impressions Severity (CGI-S) scales.
All study participants reported clinically significant symptom relief. Eighteen of the nineteen participants (94.7%) reported either “improved” or “very much improved” on the CGI-I and experienced decreased tic severity (average 60% reduction) on the Yale Global Tic Severity Scale (YGTSS). All 15 patients who reported obsessive-compulsive symptoms at baseline experienced Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score improvement, and all but 1 participant meeting ADHD symptoms according to the Adult ADHD Self-Report Scale (ASRS) continued to do so while using cannabis.
All patients reported improvement in comorbid symptoms with cannabis, including obsessive-compulsive symptoms, attention, impulsivity, anxiety, irritability, rage outbursts, and sleep. Cannabis tolerability was high among the patients, all of whom had been using cannabis for 2 years. The MEEQ did not suggest ongoing adverse effects overall, and none of the patients met the criteria for a psychotic disorder based on the SCID-I/P. However, through open ended questioning, most patients reported one or more adverse effect, including feeling “high,” cognitive effects, and anxiety. One patient had to temporarily discontinue treatment due to difficulties with irritability.
Cannabis seems to be a promising treatment option for tics and associated symptoms. However, despite the improvements reported, some patients continued to take other medications in addition to cannabis. While cannabis appears to be generally well tolerated, side effects were common. This preliminary retrospective study identifies the need for more well-designed, controlled studies to adequately characterize the benefits and risks of using medicinal cannabis for the treatment of Tourette’s syndrome.
Reference:
Abi-Jaoude, E., Chen, L., Cheung, P., Bhikram, T., & Sandor, P. (2017). Preliminary Evidence on Cannabis Effectiveness and Tolerability for Adults With Tourette Syndrome. The Journal of neuropsychiatry and clinical neurosciences, 29(4), 391–400. https://pubmed.ncbi.nlm.nih.gov/28464701/
