Clinical Trial: THC/CBD Combination Reduces Tic Frequency in Patients with Tourette Syndrome

Queensland, Australia: The consumption of plant-derived cannabinoid extracts reduces tic frequency and severity in patients with Tourette Syndrome (TS), according to placebo-controlled clinical trial data published in an imprint of the New England Journal of Medicine.

Australian investigators compared the use of cannabinoid extracts versus placebo in a cohort of patients with severe TS. Extracts contained 5 mgs of THC and 5 mgs of CBD. Doses were escalated over time to 20 mgs of THC and CBD daily. Patients underwent a six-week course of treatment.

Researchers reported: “An oral 1:1 THC:CBD formulation titrated upward over 6 weeks up to a daily dose of 20 mg of THC and 20 mg of CBD led to a significant reduction in tics as measured by the total tic score on the YGTSS [Yale Global Tic Severity Scale], as well as a reduction in obsessive-compulsive symptoms and anxiety, without major adverse effects.”

Adverse events associated with cannabis treatment were reported to be “mild.”

The study’s authors concluded: “This study adds to a small body of literature suggesting that oral 1:1 THC:CBD is an effective treatment for tics and psychiatric comorbidity associated with severe Tourette syndrome. Although the adverse-effect profile was mild in this relatively short study, further work is necessary to identify the longer-term effects of cannabis use in Tourette syndrome, such as the possible development of tolerance to the anti-tic effect. … Larger and longer trials taking the adverse-effect profile of these agents into consideration are warranted.”

Israeli data published last month reported sustained benefits in the management of TS among patients who used cannabis for several years.

Full text of the study, “Tetrahydrocannabinol and cannabidiol in Tourette Syndrome,” appears in NEJM Evidence. Additional information on cannabinoids and TS is available from NORML’s publicationClinical Applications for Cannabis and Cannabinoids.