An Efficacy and Safety Study of Long-acting Risperidone in Participants With Schizophrenia or Schizoaffective Disorders Who Are Receiving Psychiatric Home Care Treatment

The purpose of this study is to evaluate the efficacy and safety of long-acting risperidone microspheres (small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers) in participants with schizophrenia (psychiatric disorder with symptoms of emotional instability, detachment from reality, often with delusions and hallucinations, and withdrawal into the self) and schizoaffective disorders (a mixed psychiatric disorder relating to a complex psychotic state that has features of both schizophrenia and a mood disorder such as bipolar disorder), who are receiving psychiatric home-care treatment .

Inclusion Criteria: * Meet the diagnostic criteria for schizophrenia or schizoaffective disorder according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) * Participant has been given an adequate dose of an appropriate antipsychotic for an adequate period of time prior to enrollment, but previous treatment is considered unsatisfactory due to one or more of the following reasons: lack of efficacy, lack of tolerability or safety, lack of compliance and/or other reasons to switch to another antipsychotic medication * Female participants must be postmenopausal, surgically sterile, or practicing an effective method of birth control before entry and throughout the study; have a negative urine betahuman chorionic gonadotropin (HCG) pregnancy test at screening; and a negative urine pregnancy test on screening visit * Participants or their legally acceptable representatives must have signed an informed consent document Exclusion Criteria: * Participants with a primary, active DSM-IV diagnosis other than schizophrenia and schizoaffective disorder * Participants with relevant history or current presence of any significant and/or unstable cardiovascular, respiratory, neurological (including seizures or significant cerebrovascular), renal, hepatic, hematologic, endocrine, immunologic or other systemic disease * Participants that are previously on concomitant use of Risperdal CONSTA * History or current symptoms of tardive dyskinesia * History of neuroleptic malignant syndrome (NMS)