This systematic review and meta-analysis aim to evaluate the effectiveness of CBMs in treating Tourette syndrome.

Tourette syndrome (TS) is characterized by motor and vocal tics, often accompanied by obsessive-compulsive disorder (OCD) and attention-deficit/hyperactivity disorder (ADHD). Cannabis-based medicines (CBMs) offer a promising treatment due to their interaction with the endocannabinoid system, potentially reducing tics and comorbidities. Unlike conventional treatments such as antipsychotics, CBMs show better tolerability and fewer side effects. Though evidence is limited, emerging research highlights the potential of CBMs in improving the quality of life for TS patients.

We searched electronic databases (PubMed, Google Scholar, Science Direct, Cochrane) for cohort studies and randomized controlled trials (RCTs) up to June 18, 2024. Data extraction included baseline characteristics and efficacy outcomes, specifically Yale Global Tic Severity Scale (YGTSS) and Premonitory Urge for Tics Scale (PUTS) scores. The meta-analysis was performed using Review Manager version 5.4, comparing pre- and post-treatment outcomes using mean difference (MD) and 95% confidence intervals (CI).

From 1105 screened articles, eight studies were included in the systematic review and seven in the meta-analysis, involving 306 adult TS patients treated with cannabis. Significant reductions were observed in YGTSS (MD = -13.29, 95% CI [-21.67 to -4.91], P = 0.002) and PUTS scores (MD = -4.09, 95% CI [-7.24 to -0.93], P = 0.01).

CBMs show potential in reducing tics and premonitory urges in TS. Larger, placebo-controlled trials are needed to confirm these findings and optimize treatment protocols.