To evaluate the efficacy, safety, and tolerability of GSK372475 compared with placebo in the treatment of outpatient subjects with Major Depressive Disorder (MDD)

A Ten-Week, Multicenter, Randomized, Double-Blind, Placebo and Active-Controlled, Parallel-Group, Flexible-Dose Study Evaluating the Efficacy, Safety, and Tolerability of GSK372475 (1.5 mg/day to 2.0 mg/day) or Extended Release Venlafaxine XR (150 mg/day to 225 mg/day) Compared to Placebo in Adult Subjects Diagnosed with Major Depressive Disorder

Inclusion Criteria:

• Major depressive episode (MDE) associated with Major Depressive Disorder (DSM-IV-TR criteria)
• Duration of current episode is at least 12 weeks duration and less than 2 years
• Symptoms of decreased energy, pleasure, and interest
• Female subjects who agree to use acceptable methods of birth control throughout the study

Exclusion criteria:

• Current diagnosis of Panic Disorder, or symptoms of generalized anxiety or panic attacks that could interfere with their ability to complete the trial
• Symptoms of MDE better accounted for by another diagnosis
• Diagnosis of Bipolar, schizophrenia, other psychotic disorder(s), borderline or antisocial personality disorder, or dementia.
• Started psychotherapy within 3 months prior to the Screening
• Received electroconvulsive therapy or transcranial magnetic stimulation within 6 months prior to screening
• Received psychoactive drugs within 4 weeks of randomization
• Positive urine drug screen or positive blood alcohol
• Suicidal risk or has had any previous suicide attempt, a family history of suicide attempt
• Positive pregnancy test
• History of seizure disorder, myocardial infarction (< 1yr), or unstable medical condition
• Failed to respond to an adequate course of pharmacotherapy of at least 2 different antidepressants