Schizophrenia is a psychiatric disorder affecting 1% of the general population but with treatment costs accounting for approximately 2.5% of total health care expenditures.The majority of health care costs (up to 74%) are accounted for by relapse and subsequent hospitalization or institutionalized care. This protocol proposes a multicentre, retrospective and prospective observational cohort (group of individuals that have similar trait) design, determining aggregate drug usage patterns and commonly used clinical outcomes associated with the use of long-acting injectable risperidone when used as in daily practice. It is believed that such a study can efficiently deliver crucial information for decision makers.

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

Inclusion Criteria:

• Patients with schizophrenia or schizoaffective disorder - Patients who are an ambulant, or not chronically hospitalized for maximal 6 months at the moment of initiation of study - Patients and/or his/her relative, guardian or legal representative who has signed the informed consent form

Exclusion Criteria:

• Patient's first antipsychotic treatment ever(treament naïve patients)
• Participating in any other drug study - Chronically hospitalized and according to physician no prospect of being discharged within the planned observation period - On clozapine during the last 3 months - Serious unstable medical condition, including recent and present clinically relevant laboratory abnormalities - Previous sensitivity history to risperidone and treatment resistant schizophrenia - Pregnant or breast-feeding female - Female with planned pregnancy within two years