Evaluate the Efficacy and Safety of Quetiapine Fumarate (SEROQUEL) Extended Release as Monotherapy in the Treatment of Patients With Bipolar Depression

Quetiapine fumarate extended release(XR) will be administered orally, once daily in the evening. The initial dose will be 50 mg. This dose will be adjusted on Day 2 to 100 mg, on Day 3 to 200 mg, and on Day 4 to 300 mg and after.

Placebo matching quetiapine extended release(XR) 50 mg, 200 mg, and 300 mg tablets will be orally administered once daily, in the evening. The initial dose will be 50 mg. This dose will be adjusted on Day 2 to 100 mg, on Day 3 to 200 mg, and on Day 4 to 300 mg and after.