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