 This is a single-center, randomized, single-blind, placebo-controlled, ascending single oral dose study designed to evaluate the safety, tolerability, and PK of SEP-363856 and its metabolite SEP-363854 in male and female subjects with schizophrenia. This study will determine the maximum-tolerated dose MTD for a single oral dose of SEP-363856, and characterize the plasma PK profiles of SEP-363856 and its metabolite SEP-363854 in male and female subjects with schizophrenia. 