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

This is a double-blind placebo controlled study to assess the CRF1 receptor antagonist, GSK561679, for treatment of depression in adult females diagnosed with Major Depressive Disorder (MDD). A treatment regimen of 350mg/day will be utilized to assess both efficacy and tolerability. Subjects will be randomized in equal numbers (n=75/arm) to the treatment arm and the placebo arm for a 6-week treatment period. Efficacy will be assessed by determining the change from baseline in symptoms of MDD and anxiety utilizing the Bech Melancholia scale (Bech), Hamilton Rating Scale for Depression (HamD17), Inventory of Depressive Symptomatology-Self-Report (IDS-SR), Clinical Global Impression - Severity of Illness (CGI-S), Clinical Global Impression - Global Improvement (CGI-I), Medical Outcomes Study 12-item Sleep Module (MOS 12), Cohen Perceived Stress Test (PSS), Hamilton Anxiety Scale (HamA), and Dexamethasone Suppression Test (DST). Safety and tolerability will be assessed by determining the incidence of adverse events (AEs), vital signs, BMI, weight, clinical laboratory parameters, including ECGs, during the treatment and pre \& post-treatment phases, and Discontinuation Emergent Signs and Symptoms (DESS). In addition, the incidence of suicidality will be assessed by the Columbia Suicide Severity Rating Scale (C-SSRS).