A Study of Olanzapine and Fluoxetine for Treatment-resistant Depression

Inclusion Criteria: * Have single or recurrent unipolar major depressive disorder (MDD) without psychotic features by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-Text Revision (DSM-IV-TR) clinical assessment * Have a total score ≥22 on the 17-item Hamilton Depression Rating Scale (HAM-D17) at screening and randomization * Have treatment-resistant depression (TRD), defined as having failed to achieve a satisfactory antidepressant response, in the opinion of the investigator, to separate treatment courses of at least 2 different antidepressants, other than fluoxetine, of adequate dosage and duration (≥6 weeks) within the current major depressive episode Exclusion Criteria: * Have a diagnosis of Parkinson's disease or a related disorder * Have a current or lifetime diagnosis of any of the following conditions, according to DSM-IV-TR criteria: Schizophrenia; Schizophreniform Disorder; Schizoaffective Disorder; Delusional Disorder; Psychotic Disorder Not Otherwise Specified; Bipolar Disorder I or II; Delirium of any type; Dementia of any type; Amnestic Disorder; any Substance-Induced Disorder; or any Psychotic Disorder due to a General Medical Condition * Have a current diagnosis of post-partum depression or MDD with a seasonal pattern as defined in the DSM-IV-TR * Have paranoid, schizoid, schizotypal, antisocial, or borderline personality disorder (Axis II) as a comorbid or primary diagnosis, based on DSM-IV-TR criteria * Have DSM-IV-TR substance dependence/abuse or are not willing to avoid use of the substance (not including dependence on nicotine or caffeine) within 30 days of screening * Are actively suicidal in the judgment of the investigator * Have uncorrected narrow-angle glaucoma * Have had one or more seizures without a clear and resolved etiology * Have leukopenia * Have any acute, serious, or unstable medical conditions * Have an increased serum prolactin concentration at screening * Have a rate-corrected cardiac QT interval, calculated using Bazett's formula (QTc Bazett's \[Rate-corrected cardiac QT interval on electrocardiogram calculated using Bazett's formula(QTcB)\]), on Electrocardiogram (ECG) \>450 milliseconds (male) or \>470 milliseconds (female) at screening * Have a history of allergic reaction to olanzapine, fluoxetine, or olanzapine in combination with fluoxetine * Have had treatment with olanzapine, fluoxetine, or olanzapine in combination with fluoxetine withdrawn due to clinically significant and/or intolerable adverse effects within 6 months of screening * Have received treatment with remoxipride within 6 months of randomization * Have received treatment with depot antipsychotics within one dosing interval before randomization * Have received electroconvulsive therapy (ECT) or vagus nerve stimulation (VNS) treatment within the current MDD episode, or has a history of failure to respond to adequate treatment courses of ECT or VNS, or is expected to require ECT or VNS at any time during the study * Have received previous treatment with clozapine * Have received treatment with a monoamine oxidase inhibitor (MAOI) within 14 days of screening, or are expected to need MAOI treatment at any time during the study or up until 5 weeks after study discontinuation