To evaluate the efficacy of two fixed doses of SR58611A (175 mg q12 and 350 mg q12) compared to placebo in patients with Major Depressive Disorder (MDD) using paroxetine (20 mg qd) as positive control. In addition, the tolerability and safety of SR58611A in patients with MDD will be evaluated.

Inclusion Criteria:

• Patient with Major Depressive Disorder diagnosed according to Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR
• Patient meets criteria for a recurrent Major Depressive Episode (MDE)
• Patient meets severity assessments of depression specified by the study

Exclusion Criteria:

• Patient is at immediate risk for suicidal behavior
• Patient is with a unstable medical condition
• Patient with psychotic features, catatonic features, seasonal pattern or postpartum onset
• Patient has taken concomitant treatment that may interfere with valid collection or interpretation of study data
• Patient has been treated with non-pharmacologic therapy intended to treat depression in the past 6 months
• Patient has been treated with paroxetine (Paxil) within the previous 6 months
• Patient is pregnant or breastfeeding, or likely to become pregnant during the course of the study