Study Comparing the Efficacy of Venlafaxine XR Vs. SSRIs and Conventional Antidepressants in Depressed Patients

Main Inclusion Criteria:

• Males or females, 18 -65 years of age

• Outpatients

• Major depressive disorder based on DSM-IV criteria

• The baseline score of 17-item HAM-D³17

• Switchers from prior antidepressants, who have had no satisfactory improvement (normally after a minimum of 8weeks of treatment), with an approved antidepressantmedication or have experienced intolerance due to side effects to their antidepressantmedication based on clinical discretion

• Provide written informed consent

• If female is of childbearing potential, must be confirmed no pregnancy at baseline,and use a medically acceptable method of contraception throughout the study.

Main Exclusion Criteria:

• Hypersensitivity to venlafaxine;

• Clinically significant renal or hepatic disease or any other medical disease that, inthe opinion of the investigator, might compromise the study, including seizure

• Alcohol or drug abuse within the last year

• A recent history of myocardial infarction or unstable heart disease (within 6 monthsof baseline)

• Bipolar disorder

• For female, known or suspected pregnancy or breast feeding

• Use of a monoamine oxidase inhibitor (MAOI) within 14 days of baseline; use of anyinvestigational drug within 30 days of baseline.

• Patients have prior use of venlafaxine or use of venlafaxine for the current episode.