Switching From Consta® to Sustenna® in Patients With Schizophrenia

Inclusion Criteria: * Age: 18 \~ 65 * Patient with schizophrenia according to DSM-IV criteria * Patient have signed on the informed consent, and well understood the objective and procedure of this study. * Maintenance therapy more than 6 months with Risperidone Long Acting Injection monotherapy or other with concomitant antipsychotics, and stable dose of Risperidone Long Acting Injection was maintained 8 weeks more. The stable dose of other antipsychotics has been maintained 8 months and more. * Patient wants to switch antipsychotics to Paliperidone Palmitate. * PANSS total score ≤ 80 * Each score of conceptual disorganization(P2), hallucinatory behavior(P3), Suspiciousness/persecution(P6), unusual thought content(G9)in PANSS ≤ 4 * Competent patient who is manage to answer the questionnaires. * In case of female at child-bearing age, consent to use appropriate contraceptive methods(oral pill, contraceptive injection, intrauterine device, double barrier method and contraceptive patch) during entire duration of this study. Exclusion Criteria: * No history of antipsychotics use. * Past history of NMS. * Allergy or hypersensitivity to Risperidone or Paliperidone ER. * Concomitant antipsychotics was oral Risperidone or Paliperidone ER. * Initiating or dose-changing of SSRI, MAOI, TCA within 2 months(maintenance is allowed if those have been stable for at least 30days prior to study entry and would not be any dose changes during the study) * Initiating of Lithium, Valproic acid, Carbamazepine, Topiramate, Lamotrigine or other mood stabilizer within 2months (maintenance is allowed). * Patient who is supposed to be impossible to participate to this study due to clinical risk of suicide or aggressive behavior based on clinician's opinion. * Current substance dependence(DSM-IV) or past history of dependence (more than 6months) * Significant biochemical or hematological abnormality or abnormal finding of urinalysis, based on clinician's opinion. * History of cardiac disease which predispose to QT prolongation(sick sinus, complete AV block, CHF, ventricular tachycardia, hypokalemia or hypocalcemia) or current medication of QT prolonging drugs * Pregnant or breast-feeding female patient. * History of participating to other investigational drug trial within 1month prior to screening. * Investigator or employee at clinical trial center, personnel related to investigator or trial center on this or other study, or family of employee or investigator