Efficacy of Seroquel SR in Combination With an Antidepressant in Treatment of Major Depressive Disorder

Inclusion Criteria: * Male or female aged 18 to 65 years * A documented diagnosis of major depressive disorder Exclusion Criteria: * Patients with a DSM IV Axis I disorder other than MDD within 6 months of enrolment * Patients with a diagnosis of DSM IV Axis II disorder which has a major impact on the patient's current psychiatric status * Patients whose current episode of depression exceeds 12 months or is less than 4 weeks prior to enrolment