The purpose of this study is to evaluate the efficacy, tolerability and safety of patients on long-acting Risperidone microshpheres injection. The major advantage of long-acting injection over oral medication is facilitation of compliance in medication taking. Non-compliance is very common among schizophrenic and is a frequent cause of relapse.

Inclusion Criteria:

• Subjects with schizophrenia or another psychotic disorder according to DSM IV criteria who requires long term antipsychotic therapy
• Currently treated with either an atypical antipsychotic, other than risperidone, a conventional depot antipsychotic or oral conventional antipsychotic
• Subject has been symptomatically stable on a stable dose of an antipsychotic the last month
• Subject and/or patient's relative, guardian or legal representative has signed the informed consent form

Exclusion Criteria:

• First antipsychotic treatment ever
• On clozapine during the last 3 month
• Serious unstable medical condition
• History or current symptoms of tardive dyskinesia
• History of neuroleptic malignant syndrome
• Pregnant or breast-feeding female
• Female patient of childbearing potential without adequate contraception.
• Participation in an investigational drug trial in the 30 days prior to selection
• Known intolerance/non-responder to risperidone