- 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.