Patient description: A 46-year-old Asian woman with MDD complains of persistent feelings of sadness and loss of interest in daily activities. She states that her mood is still depressed most of the days. She complains of loss of energy and feelings of worthlessness nearly every day. She is on anti-depressants for the past 6 months, but the symptoms are still present. She does not drink alcohol or smoke. She used to exercise every day for at least 30 min., but she doesn't have enough energy to do so for the past 3 weeks. She also has some digestive issues recently. She is married and has 4 children. She is menopausal. Her husband was diagnosed with colon cancer a year ago and is undergoing chemotherapy. Her past medical history is unremarkable. Her family history is negative for any psychologic problems. Her HAM-D score is 20.

Clinical trial eligibility criteria: eligible ages (years): 18.0-64.0,  Depressive Disorder, Major Female outpatients aged 25-64 years, inclusive Subjects must have the ability to comprehend the consent form, and provide informed consent Subject currently meets the diagnosis for MDD (without psychotic features), single episode or recurrent, as defined in the DSM-IV-TR, diagnosed with SCID-CT (Structural Clinical Interview for DSM-IV Axis I disorders Clinical Trials Version) as assessed * by a physician with adequate training in psychiatry (e.g., Board Certification in psychiatry in the US or equivalent local qualification in other countries) Subject must, in the investigator's opinion based on clinical history, have met DSM IV-TR for their current major depressive episode for at least 4 weeks but for no greater than 24 months Subject has an IVRS HamD17 total score ≥ 23 at the Screening and Randomization Visits and the HAMD17 score is confirmed to be at least 20 by the Independent Efficacy Rater at the Screening and Randomization Visits The subject is eligible to enter and participate in this study if she is not lactating and Is of non-childbearing potential (i.e., physiologically incapable of becoming pregnant, including any female who is post-menopausal [defined as one year without menses]); is surgically sterile [via hysterectomy and/or removal of the ovaries] or, is of child-bearing potential, has a negative pregnancy test at both screening and baseline (prior to investigational product administration), and agrees to acceptable methods of contraception  Symptoms of the presenting illness which are better accounted for by another diagnosis*; or A current DSM-IV-TR Axis I diagnosis of Dementia; or Antisocial or Borderline Personality Disorder or other current DSM-IV-TR Axis II diagnosis that would suggest unresponsiveness to pharmacotherapy or non-compliance with the protocol; or A current (or within 12 months prior to the Screening visit) diagnosis of anorexia nervosa or bulimia; or A lifetime history of Schizophrenia, Schizoaffective Disorder, or a Bipolar Disorder Subject has an unstable medical disorder or a disorder that would interfere with the action, absorption, distribution, metabolism, or excretion of GSK561679 or may pose a safety concern, or interfere with the accurate assessment of safety or efficacy Subject has initiated psychotherapy within one month prior to the Screening visit, or plans to initiate psychotherapy during the trial. Subjects who present with their current MDD diagnosis despite longer-term psychotherapy (i.e., greater than three months prior to the Screening visit) and who agree to maintain the same therapy schedule during the trial may be included Subject has received vagus nerve stimulation, electroconvulsive therapy, or transcranial magnetic stimulation within the six months prior to the Screening visit Subject has previously failed adequate therapeutic courses of pharmacotherapy for MDD (e.g., maximum-labeled/tolerated doses for ≥ 4 weeks) from two different classes of antidepressants Subject, who, in the investigator's judgement, poses a homicidal or serious suicidal risk, has had any previous suicide attempt (including aborted, interrupted or ineffective attempts) or who has ever been homicidal