The purpose of this study is to demonstrate superior efficacy of sustained release quetiapine compared to placebo in patients with schizophrenia after receiving treatment for up to 6 weeks.

Inclusion Criteria:

• Patient is able to provide written informed consent before beginning any study related procedures
• Patient has a documented clinical diagnosis of schizophrenia
• Patient is able to understand and comply with the requirements of the study, as judged by a study investigator

Exclusion Criteria:

• Patients with a history of non-compliance as judged by the study investigator
• Patients with a known lack of response to previous treatment with quetiapine
• Patients who have participated in another drug study within 4 weeks prior to enrollment into this study
• Patients who have previously participated in this study or study D1444C00132