Is Medicinal Cannabis an Effective Treatment for Tourette Syndrome in Adolescents? a Pilot Study

A Pilot Randomized Placebo-controlled Crossover Trial of Medicinal Cannabis (MC) in Adolescents with Tourette Syndrome (TS)

This is a single site, pilot double-blind, randomized, placebo-controlled, cross-over study of 10 participants comparing medicinal cannabis (THC:CBD 10:15 oil) with placebo in reducing tics in adolescents aged 12 - 18 years with severe Tourette Syndrome (TS).

The primary objective of this pilot study is to evaluate all elements of the study design (recruitment strategy, study duration, study procedures, study medication tolerance and outcome measures) to assess if they are acceptable and feasible for the conduct of a full-scale randomized controlled trial of THC:CBD 10:15 oil to reduce tic severity in adolescents with TS.

The secondary objective of this study is to collect preliminary data on the safety of oral THC:CBD 10:15 oil in adolescents aged 12 to 18 years with TS.

As an exploratory aim data from clinician- and parent-rated measures will be compared across the phases to explore for a signal of efficacy on primary (tic reduction) and secondary (premonitory urges, obsessive compulsive behaviors, Attention Deficit Hyperactivity Disorder [ADHD] symptoms) outcome measures.

Inclusion Criteria:

• Males and females aged 12 - 18 years of age;
• DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) diagnosis of TS as assessed by the study clinician;
• TS severity defined as a score of 20 or higher on the Total Tic Severity section of the Yale Global Tic Severity Scale;
• No changes in either medication or other interventions in the 4 weeks prior to randomization, and intention to remain on same dose for the duration of the study;
• Participant and family have the ability to comply with the protocol requirements, in the opinion of the investigator;
• Agrees not to drive for the duration of the study.

Exclusion Criteria:

• Non-English speaking parents;
• Participant history of psychosis, schizophrenia, bipolar disorder, or major depressive disorder, or a family history of psychosis;
• Taking anti-epileptic medications which interact with medicinal cannabis: clobazam, mTOR (mammalian target of rapamycin) inhibitors (e.g sirolimus, tacrolimus), anti-cancer agents, citalopram >20mg/day, escitalopram >10mg/day;
• Abnormal liver function tests defined as ALT (alanine transaminase) > twice ULN (upper limit of normal);
• Current use of illicit drugs or medicinal cannabis, or use in the 4 weeks prior to screening;
• Pregnant or intending to become pregnant during the study, or breastfeeding;
• History of clinically significant suicidal thoughts in the prior 12 months.