Evaluation of the Potential Effects of SSR149415 on the Hypothalamic-pituitary-adrenal Axis in Outpatients With Major Depressive Disorder

Inclusion criteria : * Diagnosis of major depressive disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition-Text Revision (DSM-IV-TR) and the Mini International Neuropsychiatric Interview (MINI) criteria. Exclusion criteria: * Outpatients unwilling to be hospitalized a total of 6 nights and 8 days. * Total score of less than 21 (\<21) on the 17-item Hamilton Depression Rating Scale (HAM-D) at Visit 1 (Day -7) or Visit 5 (Day -1). * Patients whose current depressive episode is diagnosed with psychotic features, catatonic features, seasonal pattern or post-partum onset or is secondary to a general medical disorder. * Patients with alcohol dependence or abuse or substance dependence or abuse in the past 12 months according to the MINI, except nicotine or caffeine dependence. * Patients who have used the following prior to entry into Segment B: any antipsychotic within 3 months; fluoxetine within 1 month; any monoamine oxidase inhibitor (MAOI) within 2 weeks; any other antidepressant, anxiolytic, sedative-hypnotic, or mood-stabilizer (lithium, anticonvulsants) within 7 days except permitted concomitant medications * The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.