Following a 28-day Screening period and Baseline visit, eligible subjects will be enrolled into the open-label Stabilization period comprised of a 4-week Titration phase to achieve a target steady-state dose of 1.8 mg/kg/day ecopipam (2 mg/kg/day ecopipam HCl) followed by an 8-week open-label Maintenance phase. Responders to ecopipam will be randomized to ecopipam 1.8 mg/kg/day (2 mg/kg/day ecopipam HCl) or placebo in a 1:1 fashion and enter the double-blind Randomized-Withdrawal (R/WD) period at Week 12. During the 12-week R/WD period, any subject meeting Relapse criteria will be withdrawn from blinded study medication and complete end of study assessments including safety follow up visits.
