Methodology: Patients who seek treatment in our treatment resistant depression clinic and who have failed to respond to treatment with two antidepressant medications will be offered to enroll in this study. The aim is to study 20 patients who meet the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria for MDD between the ages of 21-65 years. Those subjects that receive sham stimulation will be offered to have active t-DCS stimulation for additional 3 weeks to get any benefit that they may have otherwise missed by being in the sham stimulation group.