An Eight-week Study to Evaluate the Efficacy and Safety of Saredutant in Patients With Depression

Inclusion Criteria: * 1.Male or female patients. * 2.18 to 64 years of age. * 3\. Inpatients or outpatients. * 4\. Written informed consent from the patient and/or legally authorized representative. * 5\. Able to comply with the protocol and follow written and verbal instructions. * 6\. Subjects of childbearing potential must have a confirmed negative serum b-hCG test prior to entry into Segment B and must employ an acceptable method of birth control (e.g., oral, depot, or implanted contraceptive method, IUDs, sterilization, barrier methods in conjunction with spermicide). * 7\. Diagnosis of major depressive disorder, as defined by Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text Revision criteria and confirmed by the semi-structured Mini International Neuropsychiatric Interview (MINI), recurrent episode for at least one month prior to the entry. * 8\. Minimum total score of 22 on the Montgomery-Asberg Depression Rating Scale (MADRS). Exclusion Criteria: * 1.Patients whose current depressive episode is diagnosed with psychotic features, catatonic features, seasonal pattern or post-partum onset. * 2.The duration of the current depressive episode is greater than 2 years. * 3.Patients who are currently suicidal or have a history of a suicide attempt within 3 years prior to entry. * 4.Patients whose current depressive episode is secondary to a general medical disorder. * 5.Patients with a history or presence of bipolar disorders or psychotic disorders according to the D and L criteria of the MINI. * 6.Patients with alcohol dependence or abuse or substance dependence or abuse in the past 12 months except nicotine or caffeine dependence. * 7.Patients with a history of failure to respond to treatment with paroxetine or other antidepressant medications. * 8.Patients who have used the following prior to entry into Segment B: any antipsychotic within 3 months,-fluoxetine within 35 days, -any monoamine oxidase inhibitor within 21 days, any other antidepressant, anxiolytic, sedative-hypnotic, or mood-stabilizer (lithium, anticonvulsants) within 7 days except permitted concomitant medications. * 9.Females who are pregnant or breast-feeding. * 10.Severe or unstable cardiovascular, renal, hepatic, respiratory, hematological, endocrinological, neurological, or other somatic disease that might interfere with the evaluation of study medication. * 11.History of seizures other than a single childhood febrile seizure. * 12.ECG abnormalities of potential clinical significance including a QT interval with Bazett's correction of 500 msec or more at entry. * 13.Use of known inducers or potent inhibitors of CYP3A4 within 7 days of entry. * 14.Use of drugs with known risk for Torsade de Pointes within 7 days of entry into Segment B. * 15.Participation in a clinical trial of an experimental therapy within 30 days prior to entry or prior participation in a clinical trial of saredutant. * 16.Patients with a positive HbsAg or anti-HCV antibody test at screening. * 17.Patients with any of the following at screening: ALT \>2 times the upper limit of the normal range (XULN), AST \>2XULN, GGT \>3XULN, total or conjugated bilirubin \>ULN.