• Determine comparative efficacy in patients with schizophrenia of non-inferiority of IM olanzapine depot high and low doses versus oral olanzapine based on exacerbation rates after 6 months of maintenance treatment
• Determine comparative efficacy in patients with schizophrenia of superiority of IM olanzapine depot low, med and high doses versus very low dose based on time to exacerbation of symptoms of schizophrenia

• high and low doses versus oral olanzapine based on exacerbation rates after 6 months of maintenance treatment
• and 2) superiority of IM olanzapine depot low, med and high doses versus very low dose based on time to exacerbation of symptoms of schizophrenia
• Determine the comparative efficacy in patients with schizophrenia of 1)noninferiority of IM olanzapine depot

• Demonstrate non-inferior efficacy in terms of exacerbation rates of high plus low dose IM olanzapine depot versus medium dose
• Provide information on transition of patients stabilized on oral olanzapine 10, 15 or 20 mg/day to therapeutic doses of IM olanzapine depot
• Demonstrate superiority of high dose, medium dose and low dose IM olanzapine depot compared with very low dose IM olanzapine depot in change from baseline to endpoint in PANSS total, positive, negative and general subscales
• Assess the safety and tolerability of high plus low dose IM olanzapine depot versus oral olanzapine
• Assess the safety and tolerability of medium dose IM olanzapine depot versus oral olanzapine
• Assess the safety and tolerability of each IM olanzapine depot treatment group versus very low dose IM olanzapine depot
• Compare the efficacy of high plus low dose IM olanzapine depot versus oral olanzapine during maintenance treatment on quality of life, drug attitude inventory, resource utilization and hospitalization measures
• Compare the efficacy of high, medium and low doses of IM olanzapine depot during maintenance treatment on quality of life, drug attitude inventory, resource utilization and hospitalization measures
• Characterize the pharmacokinetics of olanzapine following multiple dosing with IM olanzapine depot at each of the prescribed dosing regimens and to compare IM olanzapine depot pharmacokinetics with oral olanzapine pharmacokinetics

• 1) Demonstrate noninferior efficacy in terms of exacerbation rates of high plus low dose IM olanzapine depot versus medium dose
• 2) Provide information on transition of patients stabilized on oral olanzapine 10, 15 or 20 mg/day to therapeutic doses of IM olanzapine depot
• 3) Demonstrate superiority of high dose, medium dose and low dose IM olanzapine depot compared with very low dose
• IM olanzapine depot in change from baseline to endpoint in PANSS total, positive, negative and general subscales
• 4) Assess the safety and tolerability of high plus low dose IM olanzapine depot versus oral olanzapine
• 5) Assess the safety and tolerability of medium dose IM olanzapine depot versus oral olanzapine
• 6) Assess the safety and tolerability of each IM olanzapine depot treatment group versus very low dose IM olanzapine
• depot
• 7) Compare the efficacy of high plus low dose IM olanzapine
• depot versus oral olanzapine during maintenance treatment on
• quality of life, drug attitude inventory, resource
• utilization and hospitalization measures
• 8) Compare the efficacy of high, medium and low doses of IM olanzapine depot during maintenance treatment on quality of life, drug attitude inventory, resource utilization and hospitalization measures
• 9) Characterize the pharmacokinetics of olanzapine following multiple dosing with IM olanzapine depot at each
• of the prescribed dosing regimens and to compare IM olanzapine depot pharmacokinetics with oral olanzapine pharmacokinetics

This is a randomized, double-blind study to determine how well intramuscular (IM) olanzapine depot works compared to oral olanzapine; evaluate the safety and tolerability of IM olanzapine depot compared to oral olanzapine; evaluate different doses of IM olanzapine depot; and determine the blood levels of IM olanzapine depot in patients at different points in time after an injection.

• Drug: Intramuscular Olanzapine Depot
• Drug: Oral Olanzapine

Inclusion Criteria:

• Patients must have schizophrenia
• Patients must be clinically stable on antipsychotic medication
• Patients must be retrospectively judged by investigators, based on clinical interview and impression, to have been stable (with respect to their symptoms of schizophrenia) for at least 4 weeks entry into the study
• Patients must be an outpatient and have BPRS positive items scores of 4 or less to enter the study
• Female patients of childbearing potential must be using a medically accepted means of contraception.

Exclusion Criteria:

• Patients must not have participated in a clinical trial of another investigational drug, including olanzapine, within 1 month (30 days) prior to study entry.
• Female patients must not be pregnant or breast-feeding
• Patients must not be experiencing acute, serious, or unstable medical conditions other than schizophrenia
• Patients must not require concomitant treatment with any other medication with primarily central nervous system activity, including antidepressants, mood stabilizers, and anticonvulsants.
• Patients must not have a substance (except nicotine or caffeine) dependence within the past 30 days