Conversion to Antipsychotic Monotherapy

This is a 12-week, with a 32-week follow-up, rater-blind, randomized controlled trial to determine whether patients with chronic schizophrenia or schizoaffective disorder receiving two different antipsychotics simultaneously will have any significant change in psychopathology following conversion to antipsychotic monotherapy. Additionally, the effects of conversion to antipsychotic monotherapy will be assessed by neurocognitive tests. The study will be conducted at the Clinical Research and Evaluation Facility (CREF), a specialized research unit jointly operated by the Nathan S Kline Institute for Psychiatric Research (NKI) and Rockland Psychiatric Center (RPC). Patients will be recruited from the regular in-patient units of RPC and transferred to the CREF. Following baseline assessments, patients will be randomized to continued antipsychotic polypharmacy treatment or to systematic conversion to monotherapy. Conversion to antipsychotic monotherapy will be assessed across multiple domains of psychopathology using the Positive and Negative Symptom Scale (PANSS). The primary outcome measure is PANSS total score. The secondary outcome measure is time on medication (all-cause dropouts). Mixed Model Repeated Measures (MMRM) will test the hypothesis that conversion to antipsychotic monotherapy will show minimal change from the control group.