The study will be conducted in 3 phases:
* Screening Period (up to 14 days) during which patient eligibility will be assessed.
* Double-blind Treatment Period (DBTP) (6 weeks) during which all patients will be randomized in a 1:1:1 ratio to receive either lumateperone high dose, lumateperone low dose, or placebo as a once daily dose.
* Safety Follow-up Period (1 week) during which all patients will return to the clinic for a safety follow-up (SFU) visit approximately 1 week after the last dose of study drug.