The purpose of this trial is to evaluate the dose distribution, effectiveness and safety in patients with schizophrenia who are switched from an oral atypical antipsychotic to Paliperidone ER. In this study patients and physicians know the name and the dose of the study drug. Newly diagnosed patients will also be included in the study. In general, the recommended Paliperidone ER dose will be 6 mg once daily, however some patients may require a higher or lower initial dose in the recommended range of 3 to 12 mg once daily. The dose can be adjusted any point during the study, to a maximum dose of 12mg/day. Flexible dosing was chosen to best mimic actual clinical practice.The safety assessments to be conducted throughout this study including the regular monitoring and recording of all Adverse Events and Serious Adverse Events.

This trial is a non-randomised (both patient and physician know the study drug), single arm, open label multicentre study which is aimed to evaluate the dose distribution, efficacy and safety in patients with schizophrenia who are switched from an oral atypical antipsychotic to Paliperidone ER. Newly diagnosed patients will also be included in the study. In general, the recommended Paliperidone ER dose will be 6 mg once daily, however some patients may require a higher or lower initial dose in the recommended range of 3 to 12 mg once daily. The dose can be adjusted any point during the study, to a maximum dose of 12mg/day. Flexible dosing was chosen to best mimic actual clinical practice.The study duration will be split into two phases. Phase A will be 12 weeks and Phase B which will be an optional follow up phase will be 40 weeks. Assessment of efficacy and safety will be performed in Phase A at baseline, 2, 4, 6, 9 and 12 weeks and in Phase B at 20, 28, 36, 44 and 52 weeks. At the first visit, a full psychiatric history, demographic data and physical examination will be undertaken. Throughout the study, the following procedures, documentations and evaluations will be performed: descriptions of concomitant medications; hospitalisations for psychiatric reasons; clinical deterioration; Clinical Global Impression - Severity (CGI-S) and Global Assessment of Functioning (GAF) assessments; Community Treatment Order (CTO) status; weight; adherence and adverse event reporting. Physical examinations will be performed periodically. Paliperidone ER OROS will be supplied in 3 mg, 6 mg, and 9 mg tablets for oral administration. In general, the recommended Paliperidone ER dose will be 6 mg once daily, however some patients may require a higher or lower initial dose in the recommended range of 3 to 12 mg once daily. The dose can be adjusted any point during the study, to a maximum dose of 12mg/day. The study duration will be split into two phases. Phase A will be 12 weeks and Phase B which will be an optional follow up phase

Inclusion Criteria:

• Patients must satisfy the following criteria to be eligible for this study: patients with diagnoses of schizophrenia according to the DSM-IV criteria including newly diagnosed patients
• Out-patients or in-patients with expected discharge within 8 weeks
• Patients or their legally acceptable representatives must have signed an informed consent document indicating that they understand the purpose of and procedures required for the study and are willing to participate in the study.

Exclusion Criteria:

• Patients who meet any of the following criteria will be excluded from participating in the study: patients who are resistant to antipsychotic treatment
• Patients who have been on clozapine or long-acting injectable antipsychotic medication during the last 3 months
• Patients with CGl-S scores > 6 or who who have been hospitalized for longer than 8 continuous weeks during the past 6 months
• Pregnant or breast-feeding females
• Patients with a history or current symptoms of tardive dyskinesia or neuroleptic malignant syndrome.