This study evaluates the effect of ecopipam tablets in children and adolescents in the treatment of Tourette's Syndrome (TS). Half of the participants will receive ecopipam tablets, while the other half will receive matching placebo tablets

Multicenter, placebo-controlled, double-blind, randomized, parallel-group, Phase 2b study in pediatric subjects (aged greater than equal to 6 to less than 18 years of age) with TS. Following a 28-day Screening period and Baseline visit, eligible subjects will be randomized 1:1 to receive either ecopipam hydrochloride (HCl) or matching placebo for a 12 week treatment period. Doses will be titrated up and down from target dose of 2 mg/kg/day. Follow Up visit will be conducted after the last dose of study medication.

Inclusion Criteria:

• ≥ 6 and < 18 years of age
• ≥ 18 kg (~ 40 lbs.)
• TS diagnosis and both motor and vocal tics that cause impairment with normal routines
• Minimum score of 20 on the YGTSS-Total Tic Score
• May not be taking any medications used to treat motor or vocal tics for at least 14 days prior to Baseline.
• Effective contraception during the study and 30 days after last study dose for sexually active subjects

Exclusion Criteria:

• Certain mood or psychiatric disorders (i.e., dementia, bipolar disorder, schizophrenia, major depressive disorder)
• Unstable medical illness or clinically significant lab abnormalities
• Risk of suicide
• Pregnant or lactating women
• Moderate to severe renal insufficiency
• Hepatic insufficiency
• Positive urine drug screen
• Unstable doses for drugs to treat anxiety, depression, Attention Deficit Hyperactivity Disorder
• Certain medications that would lead to drug interactions
• Recent behavioral therapy