Lurasidone (lurasidone HCl) is a novel psychotropic agent that is being developed as a potential new antipsychotic treatment for patients with schizophrenia. Switching between antipsychotic medications is common in the treatment of schizophrenia. The current study is designed to evaluate the effectiveness, safety, and tolerability of switching clinically stable, but symptomatic outpatients with schizophrenia or schizoaffective disorder from their preswitch antipsychotic medication to lurasidone, over a period of 6 weeks.

Inclusion Criteria:

• Subject ≥ 18 years of age.
• Subject meets DSM-IV criteria for a primary diagnosis of schizophrenia or schizoaffective disorder.
• Subject must be judged by the investigator to be an appropriate candidate for switching current antipsychotic medication due to insufficient efficacy and/or safety or tolerability concerns.

Exclusion Criteria:

• Presence of an Axis I or Axis II disorder other than schizophrenia or schizoaffective disorder that is the primary focus of treatment prior to screening.
• Subject has experienced persistent lack of improvement in psychotic symptoms despite adequate trials (at least 6 weeks at standard doses), of two or more antipsychotic agents in the 12 months prior to screening.
• Subject is considered by the investigator to be at imminent risk of suicide or harm to self, others, or property. Subject has suicidal ideation at baseline or has attempted suicide within 90 days prior to randomization (even without hospitalization).