Optimizing Response in Psychosis Study

Inclusion Criteria: * Current DSM-IV-defined diagnosis of schizophrenia, schizophreniform disorder, schizoaffective disorder, or psychotic disorder NOS as assessed using the Structured Clinical Interview for Axis I DSM-IV Disorders (SCID-I/P) (First et al, 1998) * Is in the first episode of illness. First episode is defined as having had 6 months or less of lifetime treatment with an antipsychotic. * Has not responded sufficiently to treatment with an antipsychotic. Lack of response is defined as a rating at study entry of 4 (moderate) or more on at least one of the following BPRS-A items: conceptual disorganization, grandiosity, hallucinatory behavior, unusual thought content. * Continuous antipsychotic treatment at the time of study entry of a minimum of 12 weeks with the same antipsychotic agent. * Antipsychotic dosing at some point during the 12 weeks must have reached a sufficient dose for antipsychotic response (e.g. patients who received only low dose quetiapine for insomnia or anxiety would not qualify). Sufficient dose for second generation antipsychotics is defined as a minimum dose of risperidone 3 mg/day, olanzapine 10 mg/day, quetiapine 500 mg/day, ziprasidone 100 mg/day or aripiprazole 15 mg/day. Sufficient dose for first generation antipsychotics is defined as 3 mg/day of haloperidol or its equivalent for other first generation agents. * Aged 15 to 40. * If age 18 or older, competent and willing to sign informed consent. * If under age 18, parent or guardian consent and subject assent. * For women, a negative urine pregnancy test and agreement to use a medically accepted method of birth control. Exclusion criteria: * Meets DSM-IV criteria for a current substance-induced psychotic disorder, a psychotic disorder due to a general medical condition, delusional disorder, brief psychotic disorder, shared psychotic disorder, or a mood disorder (major depression or bipolar) with psychotic features. * Persistence of psychotic symptoms due to nonadherence to antipsychotic medication. * Medical contraindications to treatment with long-acting injectable risperidone. * Serious neurological or endocrine disorder or medical condition /treatment known to affect the brain. * A medical condition requiring medication with psychotropic effects. * Clinical assessment that trial participation is contraindicated due to risk for homicidal or suicidal behavior. * A diagnosis of diabetes (fasting glucose \> 126 mg/dl). * Requires with antidepressant or mood stabilizing medication. * Previous treatment with a long acting formulation of an antipsychotic