A 6 week double blind trial of lumateperone for patients, age 18-75, currently experiencing a manic or mixed episode (cannot be the first). Patients will be admitted to the HCA West Florida Behavioral Health Unit at screening for 1 week washout of current medications and two weeks of double-blind treatment. If stable at the end of week 3, patient can be discharged to continue the study outpatient at IPTB. The compensation is up to $3600 throughout the duration of the 7 visits. Travel is provided to and from the hospital. All care is managed by the IPTB team.