Medical Cannabis Shows Promise for Adolescents With Tourette Syndrome, Study Finds

OG Article By Anthony Martinelli in News, Studies

July 11, 2025

Conducted by researchers from the University of New South Wales, the Royal Children’s Hospital, and the University of Melbourne, the open-label, single-arm trial involved 10 participants aged 12 to 18 years. Over the course of 85 days, each was given a medicinal cannabis product containing a 10:15 ratio of THC to CBD, with dosages ranging from 5 to 20 mg per day based on individual body weight and response.The study reported statistically significant improvements in parent- and clinician-reported tic severity, emotional and behavioral challenges, and quality of life. These effects were maintained even under a conservative statistical correction, strengthening the signal of potential efficacy. The strongest response was observed in parent-reported tic severity, measured by the Parent Tic Questionnaire, and in quality-of-life indicators assessed via the Gilles de la Tourette Syndrome Quality of Life scale.

Importantly, the treatment was well tolerated. No serious adverse events were recorded. The most common side effects included drowsiness, dry mouth, and tiredness—typically mild and manageable. Seven participants required a dose increase, and a few reported symptom relief after adjusting to twice-daily dosing. Only one participant withdrew, citing travel rather than safety or efficacy concerns.

While ADHD and anxiety were common comorbid conditions in the group, premonitory urges and ADHD symptoms did not significantly change during the trial. However, baseline emotional and behavioral difficulty scores were associated with better treatment responses, suggesting that individual traits could play a role in determining efficacy.

The authors emphasize that larger, randomized controlled trials are needed to confirm these preliminary findings. Still, the results provide early support for the feasibility, safety, and potential effectiveness of cannabis-based therapies for adolescents with Tourette syndrome—a population for which treatment options remain limited.