The purpose of the study is to assess the effectiveness and safety of long-acting injectable risperidone in the treatment of patients in the early stage of psychosis

Although many schizophrenia patients currently take oral antipsychotic medications, it is estimated that up to 75% of them have difficulty adhering to the daily oral regimen. Long-acting injectable formulations may eliminate the need for daily medication and enhance patient compliance with the treatment regimen. This study is a pilot project to demonstrate that long-acting risperidone can be used safely and effectively in treating patients in the early stage of psychosis. It is an open-label, single-arm study in patients with recent onset of schizophrenia, schizophreniform disorder, or schizoaffective disorder. There are 3 phases: Wash-out Phase of 7 days, during which current psychotropic medications are discontinued; Oral Treatment Phase, beginning 1 week before the first injection and continuing 3 weeks thereafter, during which risperidone tablets are taken; and Long-Acting Injectable Treatment Phase, during which injections are given every 2 weeks for 24 months. Assessments of effectiveness include Positive and Negative Syndrome Scale (PANSS), a scale for the measurement of symptoms of schizophrenia; time from initiation of treatment to relapse; Calgary Depression Scale for Schizophrenia (CDSS), which assesses symptoms of major depressive disorder in patients with schizophrenia; and Clinical Global Impression (CGI) scales. Safety assessments include the incidence of adverse events and Extrapyramidal Symptom Rating Scale (ESRS) scores throughout the study; clinical laboratory tests (hematology and chemistry) and vital signs (pulse, blood pressure, temperature) at stated intervals. Risperidone oral tablets once daily (1 milligram[mg], 2mg, or 3mg [maximum]) from 1 week before first injection through 3 wks after. Risperidone injections (25mg, 37.5mg, or 50mg [max]) every 2 weeks for 24 months. Doses may be increased or decreased at investigator's discretion.

Inclusion Criteria:

• Meet the criteria of the Diagnostic and Statistical Manual of Mental Diseases, 4th edition (DSM-IV) for schizophreniform disorder, schizophrenia, or schizoaffective disorder for no longer than 12 months, and with not more than two hospitalizations for psychosis
• patients who have, during their lifetime, been exposed to a maximum of 12 weeks of antipsychotic medication
• patients who will require at least 12 months of treatment

Exclusion Criteria:

• DSM-IV axis I diagnosis other than schizophreniform disorder, schizophrenia, or schizoaffective disorder
• patients requiring treatment with mood stabilizers or antidepressants at study initiation
• alcohol or drug abuse or dependence, according to DSM-IV criteria
• history of drug allergy, drug hypersensitivity (including risperidone), or neuroleptic malignant syndrome, a rare psychotropic-drug reaction, which may be characterized by confusion, reduced consciousness, high fever or pronounced muscle stiffness
• previous treatment with an injectable antipsychotic medication
• pregnant or nursing females, or those lacking adequate contraception