Safety and Efficacy of Cannabis in Tourette Syndrome

Inclusion Criteria: * Male or female adult, 18-65 years of age (inclusive) at the time of signing the informed consent. * The subject meets current DSM-5 diagnostic criteria for TS\[6\], diagnosed by a neuropsychiatrist with expertise in TS and related conditions. * YGTSS-TTS ≥16, frequency subscore = 5 and intensity subscore ≥ 2. In addition, tic free intervals do not last more than two minutes based on both self-reporting and observation by clinician at both screening and Week 0 (randomization). This requirement is for the purpose of minimizing the potential for floor effects given the relatively short window for assessing effect on symptoms in this single-dose trial. * The subject is able and willing to refrain from using any non-study cannabis during the screening and treatment phases of the study. * Females of childbearing potential (defined by menarche and not having undergone surgical sterilization/hysterectomy) must have a negative pregnancy test, must be practicing acceptable double-barrier methods of contraception (or can confirm abstinence at each scheduled visit), and must not be breast feeding. * Written informed consent must be obtained from the subject prior to the initiation of any protocol-required procedures. * The subject is able to comprehend and satisfactorily comply with the protocol requirements. Exclusion Criteria: * • The subject and/or his/her family have a history of psychosis, schizophrenia or bipolar disorder. * Sexually active females of childbearing potential who will not commit to utilizing 2 of the approved birth control methods or who will not remain abstinent during the trial; Females who are breast-feeding and/or who have a positive serum pregnancy test result prior at the time of screening. * The subject represents a significant risk of committing suicide (current suicide plan or attempt in past 2 years) or committing homicide. * The subject has a history of serious head injury, seizure disorder, or developmental delay (intelligence quotient≤85). * The subject has either of: cardiovascular disease; respiratory disease such as chronic obstructive pulmonary disease (COPD) or lung cancer (asthma is not an exclusionary criterion); hepatitis. * The subject has a current or past history of substance abuse within the last 5 years, with the exception of cannabis. * The subject is using cannabis regularly for the treatment of TS. * The subject has any abnormal laboratory tests and vital sign results which in the investigator's judgment is medically significant and would impact the safety of the subject or the interpretation of the study results.