Cannabis-Based Medicine Reduced Tic Severity in Tourette Syndrome | Research

The takeaway

A meta-analysis of 9 studies found cannabis-based medicine significantly reduced tic severity and premonitory urges in Tourette syndrome patients, though study sizes were small.

Tourette syndrome patients, neurologists, and medical cannabis researchers

Significant reduction in tic severity (p = 0.02) and premonitory urges (p = 0.0007)

What the researchers found

Cannabis-based medicine produced a significant reduction in Yale Global Tic Severity Scale scores (MD = -23.71, p = 0.02) and Premonitory Urge for Tics Scale scores (MD = -5.36, p = 0.0007). There was no significant effect on obsessive-compulsive symptoms as measured by the Y-BOCS (p = 0.06).

Why it matters

Tourette syndrome has limited treatment options, and existing medications (mainly neuroleptics) come with significant side effects. Cannabis-based medicine represents a potential alternative, and this is the first meta-analysis to pool the available evidence on its effectiveness for tics.

The numbers in context

9 studies reviewed, 3 included in meta-analysis. 401 patients total. YGTSS total score reduction: MD = -23.71 (95% CI: -43.86 to -3.55, p = 0.02). PUTS reduction: MD = -5.36 (95% CI: -8.46 to -2.27, p = 0.0007). Y-BOCS: non-significant (p = 0.06).

How the study worked

Systematic review and meta-analysis searching PubMed, Cochrane, Scopus, and Web of Science through February 2024. Nine studies were included in the systematic review and three in the meta-analysis, involving 401 adult patients with Tourette syndrome.

What this study cannot tell us

Only 3 of 9 studies could be pooled for meta-analysis, reflecting small and heterogeneous literature. Total sample was only 401 patients. The confidence interval for the YGTSS reduction was wide (-43.86 to -3.55), indicating high uncertainty. Most studies lacked placebo controls.

How to read the evidence

Meta-analysis provides the strongest study design, but the small number of poolable studies and wide confidence intervals temper the strength.

When this study was published

2024 meta-analysis

The bigger picture

The endocannabinoid system has known interactions with the basal ganglia circuits involved in tic generation. These results, while preliminary, provide a biological rationale for further investigation of cannabinoid therapies in movement disorders beyond just Tourette syndrome.

Questions still open

Which cannabinoid compounds are most effective for tics: THC, CBD, or combinations? What are the long-term effects of cannabis-based medicine on tic severity? Would larger placebo-controlled trials confirm these findings?

Common questions

Can cannabis help with Tourette syndrome tics?

This meta-analysis found significant reductions in tic severity and premonitory urges with cannabis-based medicine. However, the evidence is still based on small studies and needs confirmation in larger trials.

Did cannabis help with the OCD symptoms in Tourette syndrome?

The reduction in obsessive-compulsive symptom scores did not quite reach statistical significance (p = 0.06), though it trended in a positive direction.

Read the original research

Efficacy of cannabis-based medicine in the treatment of Tourette syndrome: a systematic review and meta-analysis.

European journal of clinical pharmacology, 80(10), 1483-1493

View on PubMed ↗Publisher’s paper ↗

Citation

Serag, Ibrahim; Elsakka, Mona Mahmoud; Moawad, Mostafa Hossam El Din; Ali, Hossam Tharwat; Sarhan, Khalid; Shayeb, Sally; Nadim, Islam; Abouzid, Mohamed. (2024). Efficacy of cannabis-based medicine in the treatment of Tourette syndrome: a systematic review and meta-analysis.. European journal of clinical pharmacology, 80(10), 1483-1493. https://doi.org/10.1007/s00228-024-03710-9