RecruitingPhase 4Drug trialMetabolic Effects of Adjunctive Lumateperone Treatment in Clozapine-Treated Patients With SchizophreniaThe main question this study is trying to answer is whether lumateperone, an FDA-approved antipsychotic drug, can help reduce possible side effects of clozapine, such as weight gain and elevated levels of sugar and bad cholesterol. Participants will be randomly assigned to either take lumateperone (Caplyta) or a placebo for 12 weeks, in addition to their regularly prescribed clozapine. During their participation, patients will answer questions about their psychiatric and daily functioning, have blood drawn, and have their body composition analyzed (similar to stepping on a scale).