Seroquel in Bipolar Depression Versus Lithium

Inclusion Criteria: * Patients with a diagnosis of bipolar I disorder or bipolar II disorder, currently depressed, aged 18 to 65 years old and outpatient status at enrolment and randomization. Exclusion Criteria: * Patients with a current DSM-IV Axis I disorder other than bipolar disorder that is symptomatic or requiring treatment within 6 months of enrolment, * History of non-response to an adequate treatment * Patients who, in the investigator's judgment pose a current serious suicidal or homicidal risk * Pregnancy or lactation * Clinically relevant disease or clinical finding