Efficacy of a Therapeutic Combination of Dronabinol and PEA for Tourette Syndrome

Examining the Efficacy of a Therapeutic Combination of Dronabinol (Synthetic Δ9-tetrahydracannabinol) and Palmitoylethanolamide for Tourette Syndrome

This is an investigator-initiated proof of concept study with the purpose to examine the safety, tolerability and feasibility of Dronabinol (synthetic Δ9-THC) and PEA for the treatment of adults with Tourette syndrome.

The investigators propose a 12-week, investigator-initiated, open-label trial of a therapeutic combination of Dronabinol and PEA in 18 adults with Tourette syndrome. Participants will receive Dronabinol and PEA in combination for the duration of the trial. The goal for this pilot study is to (1) provide initial safety, feasibility and tolerability data on both Dronabinol and PEA in a TS population and (2) provide data in order to make a more informed decision regarding the appropriate sample size and design of a larger clinical trial to prove efficacy (i.e. sample size and trial duration in large efficacy trial of the Dronabinol/PEA combination in TS).

Inclusion Criteria:

• Adult between 18-60 years of age
• Meet DSM-5 criteria for the diagnosis of Tourette syndrome
• Significant current tic symptoms: YGTSS total tic score greater than or equal to 22 at baseline
• On stable psychiatric medication regimen for a minimum of 4 weeks prior to beginning the trial
• Accepted method of birth control

Exclusion Criteria:

• Comorbid bipolar disorder, psychotic disorder, substance use disorder, developmental disorder or intellectual disability (IQ<70)
• Recent change (less than 4 weeks) in other medications that have potential effects on tic severity (such as alpha-2 agonists (guanfacine, clonidine or prazosin), SSRIs, clomipramine, naltrexone, lithium, anxiolytics, topiramate, baclofen etc.). Medication change is defined to include dose changes or medication discontinuation.
• Recent change in behavioral treatment for Tourette syndrome or comorbid conditions (i.e. OCD) within the last 4 weeks or initiation of behavioral therapy for tics within the last 12 weeks.
• Taking any co-medications (over the counter or prescription), food supplements/additives which can have a drug interaction with dronabinol or PEA.
• Positive pregnancy test or drug screening test
• History of cannabis dependence
• Significant Medical Comorbidity
• History of hypersensitivity to any cannabinoid or sesame oil