Risperidone is a selective monoamine receptor antagonist. It plays an antipsychotic effect by antagonizing 5-HT2 / D2 receptor. As a second-generation antipsychotic drug, risperidone is metabolized to 9-hydroxy Risperidone in the body very quickly. There are individual differences in the pharmacokinetics and pharmacodynamics of risperidone. For example, CYP2D6 genotype can greatly affect the metabolism of risperidone, and provide evidence for adjusting the type and dose of medication to treat Schizophrenia. In this study, we will verify the correlation between the polymorphisms of genes related with risperidone drug metabolites, drug transporters, drug targets and drug metabolism, pharmacodynamics, adverse reactions in Chinese population, providing basis for clinical rational use of risperidone.

Subjects with schizophrenia will be recuited from several sub-centers. The relevant gene polymorphisms and risperidone drug metabolism, drug adverse reaction parameters are monitored through drawing blood samples at 0h, 6h, D27 and D56 of the risperidone drug administration. Information related to drug pharmacokinetics, pharmacodynamics and adverse reactions(serum prolactin levels) will be collected and analyzed.

Inclusion Criteria:

• patients that meet with DSM-IV-TR schizophrenia diagnostic criteria, based on concise International Neuropsychiatric Interview (MINI);
• patients who have never received risperidone treatment or who need re-administration of risperidone after previous treatment with risperidone;
• Subjects and / or their guardians who agree to sign the informed consent.

Exclusion Criteria:

• patients who use CYP2D6 or CYP3A4 inducers or inhibitors as treatment drugs;
• patients with hepatic insufficiency;
• patients with renal insufficiency;
• patients who use other drugs that interact with risperidone;
• certain patients that the researchers consider to be unsuitable for the clinical trail.

Schizophrenic patients who are going to be treated with risperidone.