The purpose of this trial is compare the efficacy of olanzapine and Lithium Carbonate in the treatment of bipolar disorder, manic or mixed episodes, in Chinese patients.

Inclusion Criteria:

• Male or female in- or out-patients at least 18 years of age
• Patient must have a diagnosis of bipolar I disorder and currently display acute manic or mixed episodes (with or without psychotic features) according to the DSM-IV based on clinical assessment
• Patients must have a level of understanding sufficient to agree to all tests and examinations required by the protocol
• Patients must have a Y-MRS total score of greater than or equal to 20 at both visits 1 & 2
• Patients must be considered reliable

Exclusion Criteria:

• Have received treatment within the last 30 days with a drug that has not received regulatory approval for any indication at the time of study entry
• Serious, unstable illnesses including hepatic, renal, gastroenterologic, respiratory, cardiovascular, endocrinologic, neurologic, immunologic, or hematologic disease such that death is anticipated within 1 year or intensive care unit hospitalization for the disease is anticipated within 6 months
• Current or past diagnosis of schizophrenia or other psychotic disorder (including schizophreniform disorder, schizoaffective disorder, delusional disorder, brief psychotic disorder, shared psychotic disorder, psychotic disorder due to a general medical condition, substance-induced psychotic disorder, psychotic disorder not otherwise specified) as defined in the DSM-IV
• Documented history of intolerance to olanzapine or Lithium Carbonate
• Treatment with clozapine within 4 weeks prior to visit 2. Treatment with other antipsychotic drugs or mood stabilizers within 2 days prior to visit 2