The Screening Period will last a minimum of 3 to a maximum of 30 days. At the first screening visit (Visit 0), informed consent will be obtained. The Structured Clinical Interview for DSM-IV (SCID) will be performed to establish whether the patient meets DSM-IV criteria for bipolar disorder I, II, or NOS. The YMRS(17), IDS (18), and CGI-BP (16) will be performed to establish the presence and severity of bipolar affective symptoms. If subjects are currently on psychotropic medications, these will be tapered. Subjects will need to be off any psychotropic medications for at least 1 week prior to randomization, 2 weeks if you have been taking fluoxetine and 4 weeks if you have been receiving depot antipsychotic medication. Mood charts will be administered to subjects to help them in following their symptoms. Subjects will meet with the study staff weekly during the period after they have stopped their previous psychiatric medications and before they start study medication. Medical history will be reviewed, a physical exam performed, electrocardiogram (EKG) and laboratory studies (Complete Metabolic Profile, Liver Function Tests (LFT's), CBC with diff + platelets, and Urinalysis) will be obtained. Based on these evaluations, it will be determined whether subjects meet entry criteria; subjects meeting these criteria will continue in the screening process.