The purpose of this study is to evaluate symptomatic remission rate in patients with schizophrenia using long acting risperidone microspheres

Although most of Korean schizophrenic patients currently take oral antipsychotic medications, it is estimated that up to 75% of them have difficulty adhering to daily oral regimen. Long-acting injectable formulation may eliminate this need for daily medication. This is a prospective, open-label, multicenter study to determine the long-term efficacy, especially symptomatic remission rate of long-acting risperidone microspheres administrered in the muscle at 2 week intervals in patients with schizophrenia.

The patients will receive intramuscular injections either 25, 37.5, 50 mg equivalent of risperidone at every 2 weeks for 1 year

Inclusion Criteria:

• Subjects with schizophrenia or schizoaffective disorder - Subjects who have experienced relapse or re-admission previously - Subject and/or his/her relative, guardian or legal representative who has signed the informed consent form

Exclusion Criteria:

• First antipsychotic treatment ever - On clozapine during the last 3 months - Serious unstable medical condition, including recent and present clinically relevant laboratory abnormalities - Subjects that are previously on concomitant use of Risperdal Consta within 60 days prior to entry - Previous sensitivity history to risperidone - History or current symptoms of tardive dyskinesia - History of neuroleptic malignant syndrome - Pregnant or breast-feeding female - Female patient of childbearing age without adequate contraception (adequate contraception includes: abstinence, oral contraceptive, intrauterine devices, barrier method (diaphragm or condom) plus spermicide - Norplant TM or Depo-Provera TM. A female patient of childbearing potential must have an adequate contraception and a negative urine pregnancy test at every visit)