A 24-52-week Study to Evaluate the Long-term Efficacy and Safety of Saredutant in Patients With Depression (MAGENTA)

Inclusion Criteria: * Diagnosis of major depressive disorder, as defined by Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV) criteria and confirmed by the semi-structured Mini International Neuropsychiatric Interview (MINI), recurrent episode. Exclusion Criteria: * Total score of 28 or less on the Montgomery and Asberg Depression Rating Scale (MADRS). * Clinical Global Impression (CGI) severity score of less than 4. * Duration of the current depressive episode less than 2 months or greater than 2 years. * Elderly patients with a Mini-Mental State Examination (MMSE) total score \<25. * Patients with a history or presence of bipolar disorders or psychotic disorders. * Patients with alcohol dependence or abuse or substance dependence or abuse in the past 12 months except nicotine or caffeine dependence. * Benzodiazepine or sedative-hypnotic use greater than 2 days per week during the month prior to entry into the Acute Phase. * Patients who have used the following prior to entry into Acute Phase: antipsychotics within 3 months, fluoxetine within 1 month, Monoamine oxidase inhibitors (MAOIs) within 2 weeks, other antidepressant or mood-stabilizer (lithium, anticonvulsants) within 1 week. The investigator will evaluate whether there are other reasons why a patient may not participate.