4. Patients who have reported a history for the current depressive episode of an inadequate response to at least one and no more than three adequate antidepressant treatments. An inadequate response is defined as less than a 50% reduction in depressive symptom severity, as assessed by the MGH ATRQ administered by remote, independent raters. An adequate trial is defined as an antidepressant treatment for at least 6 weeks duration at least at a minimum dose as specified in the MGH ATRQ.