The Effect of Medical Cannabis on Tics, Premonitory Urge and Psychiatric Comorbidity in Adults With Tourette Syndrome

The Effect of Medical Cannabis on Tics, Premonitory Urge and Psychiatric Comorbidity in Adults With Tourette Syndrome

Medical cannabis (MC) is a standard treatment in Israel to adults with resistant Gilles de la Tourette syndrome (GTS). While small randomized control trials assessed THC efficacy on tics and premonitory urge, only small retrospective studies assessed MC efficacy and tolerability in GTS. Herein, By using an open-label, prospective design, our aim is to determine the preferred method of use, efficacy and tolerability of 12 weeks of treatment with MC in adult patients with GTS.

Gilles de la Tourette syndrome (GTS) is a childhood onset neuropsychiatric disorder characterized by the presence of multiple motor and one or more phonic tics continuing for at least one year. In Israel, although consumption of cannabis is outlawed, there is an option to allow patients to consume the drug under supervision. Medical Cannabis (MC) consumed by inhalation of smoked or vaporized dried female buds, or subligual oil extract of whole plant, has been an approved treatment by the Ministry of Health (MOH) for resistant GTS since 2013. Previous studies suggested that MC has a good effect on tics, quality of like and with good tolerability among patients with resistant GTS.

In the current study, we prospectively followed-up patients eligible for MC according to MOH restrictions, at our GTS clinic at the Tel-Aviv Sourasky Movement Disorders Unit (MDU). Each subject signed a written informed consent before inclusion in the trial. Also, since driving under the influence of cannabis is forbidden by the Israeli law, patients were instructed and gave their oral commitment to avoid driving. The study was approved by the research ethics (Helsinki) committee at our center. MC was consumed as oil extract, vaporized, or smoked dried buds. The treating neurologist (S.A.) and patient together decided on the method of consumption during the visit before initiating treatment. Patients were assessed 4 and 12-weeks following treatment initiation to gather data regarding treatment efficacy, tolerability and SEs.

Inclusion Criteria:

• Age 18 - 65 years
• Diagnosis of GTS confirmed by the treating neurologist based on the DSM-V criteria
• Eligibility to receive MOH MC license for GTS
• Provided written informed consent

Exclusion Criteria:

• Regularly use cannabis in any form for self-medication prior to entering the study
• Pregnant or lactating women
• Have a tic disorder other than GTS
• Have concurrent physical or mental disease that could interfere with the study