Efficacy of Quetiapine XR Versus Divalproex on Clinical Outcome Quality of Sleep and Quality of Life in Bipolar Depression

Inclusion Criteria: * Provision of written informed consent * A diagnosis of Bipolar depression by Diagnostic and Statistical Manual of Mental Disorders- Fourth Edition (DSM-IV) * Females and males aged 20 to 65 years * Female patients of childbearing potential must be using a reliable method of contraception and have a negative urine human chorionic gonadotropin (HCG) test at enrollment * Able to understand and comply with the requirements of the study * HAM-D score at Visit 0 and Visit 1 should be above 20. * Willingness to adhere to the schedule of assessments * Able and willing to comply with self-administration of study drug, or have consistent help or support available Exclusion Criteria: * Pregnancy or lactation * Any DSM-IV Axis 1 disorder not defined in the inclusion criteria * Patients who, in the opinion of the investigator, pose an imminent risk of suicide or a danger to self or others * Known intolerance or lack of response to quetiapine fumarate or divalproex, as judged by the investigator * Use of any of the following cytochrome P450 3A4 inhibitors in the 14 days preceding enrollment including but not limited to: ketoconazole, itraconazole, fluconazole, erγthromycin， clarithromycin, troleandomycin, indinavir, nelfinavir，ritonavir, fluvoxamine and saquinavir * Use of any of the following cytochrome P450 3A4 inducers in the 14 days preceding enrollment including but not limited to: phenytoin, carbamazepine, barbiturates, rifampin， St. John's Wort, and glucocorticoids * Administration of a depot antipsychotic injection within one dosing interval (for the depot) before randomisation * Substance or alcohol dependence at enrollment (except dependence in full remission,and except for caffeine or nicotine dependence) ， as defined by DSM-IV criteria * Opiates, amphetamine, barbiturate, cocaine, cannabis, or hallucinogen abuse by DSM-IV criteria within 8 weeks prior to enrollment * Medical conditions that would affect absorption, distribution, metabolism, or excretion of study treatment * Unstable or inadequately treated medical illness (e,g, congestive heart failure,angina pectoris, hypertension) as judged by the investigator Invo1vement in the planning and conduct of the study * Previous enrollment or randomisation of treatment in the present study. * Participation in another drug trial within 8 weeks prior enrollment into this study or longer in accordance with local requirements A patient with Diabetes Mellitus (DM) fulfilling one of the following criteria: * Unstable DM defined as enrolment glycosylated hemoglobin (HbAlc) \> 8.5% * Admitted to hospital for treatment of DM or DM related illness in past 12 weeks * Not under physician care for DM * Physician responsib1e for patient's DM care has not indicated that patient's DM is controlled * Physician responsible for patient's DM care has not approved patient's participation in the study * Has not been on the same dose of oral hypoglycaemic drug(s) and/or diet for the 4 weeks prior to randomisation. For thiazolidinediones (glitazones) this period should not be less than 8 Weeks * Taking insulin whose daily dose on one occasion in the past 4 weeks has been more than 10% above or below their mean dose in the preceding 4 weeks Note: If a diabetic patient meets one of these criteria, the patient is to be excluded even if the treating physician believes that the patient is stable and can participate in the study * An absolute neutrophil count (ANC) of s 1.5 x 109 per liter