A Study of the Effects of a New Antidepressant Treatment (GSK561679) in Females With Major Depressive Disorder

Inclusion criteria

• 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 criteria 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.

Exclusion Criteria

• 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.
• Subject has no contact with an adult on a daily basis (i.e., subjects who are not living with at least one other adult or subjects who do not have an adult who contacts them on a daily basis). This criterion only applies to sites in Canadian sites and others where this is a local requirementa.
• Subject has a positive urine test at screening for illegal drug use and/or history of substance abuse or dependence (alcohol or drugs as defined by DSM-IV TR criteria) within the past 12 months. Subject has a blood alcohol level of ≥ 15mg/dL (0.015%) at the Screening Visit. If a subject has a positive blood alcohol or positive illegal drug results, the subject is provisionally excluded and the test cannot be