Best Event Schizophrenia Trial--A Randomized Double-Blind Trial of Aripiprazole and Risperidone in Schizophrenia

Inclusion Criteria: 1. Subjects will meet DSM-IV diagnostic criteria for schizophreniform disorder, schizophrenia, schizoaffective disorder or (non-affective) psychotic disorder, NOS. Subjects with schizophreniform disorder or psychotic disorder, NOS, will be diagnostically reevaluated (recontacted if no longer involved in the study) after a minimum of six months of psychotic symptoms in order to determine whether diagnostic criteria for schizophrenia or schizoaffective disorder have been met. 2. Subjects will be between 18 and 55 years of age, inclusive. 3. Subjects will be able to fully participate in the informed consent process, or have a legal guardian able to participate in the informed consent process. 4. Present score on at least one PANSS psychosis items (P1, P2, P3, P5 or P6) \> 4(moderately severe) and CGI Severity score \> 4 (moderate). 5. Female patients of childbearing potential must be using a medically accepted means of contraception Exclusion Criteria: 1. Current active substance use disorder diagnosis or a history of cocaine abuse or dependence; 2. Female patients who are either pregnant or nursing; 3. Known history of mental retardation, seizure disorder, or a clinically significant head injury (prolonged loss of consciousness, neurological sequelae, or demonstrated structural brain injury); 4. Non-English speaking (mastery of English insufficient to participate in study evaluation procedures); 5. Serious, unstable medical illness; 6. Known hypersensitivity to any study medication; 7. Medical contraindication to any element of the study procedure; 8. Current symptoms which present serious risk of danger to self or others; 9. Participation in a clinical trial of an investigational drug within 30 days of study entry; 10. Current severity of psychiatric symptoms contraindicates a delay in initiation of antipsychotic medication treatment until functional imaging studies and neuropsychological testing have been completed; 11. Baseline QTc interval of \> 450 msec.