This study is an open-label, randomized, multi-center study conducted in a typical psychiatric outpatient practice in China. This study is intended to collect data on the efficacy and safety of venlafaxine XR (Efexor XR®) versus SSRIs and conventional antidepressants in depressed patients that previously failed antidepressant treatment. This data will be used to guide psychiatrists on recommendations for clinic use.

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 antidepressant medication or have experienced intolerance due to side effects to their antidepressant medication 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, in the 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 months of 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 any investigational drug within 30 days of baseline.
• Patients have prior use of venlafaxine or use of venlafaxine for the current episode.

The PIs agreed to allow the sponsor 60 days to review and require changes to presentations or publications but only to protect confidential information and intellectual property, and for the sponsor to file a patent application, as applicable. The PIs also agreed for data to be presented first as a joint, multi-center publication.