Major Depression is one of the most common and costly of all psychiatric disorders. While depression can be effectively treated in the majority of patients by either medication or some form of evidence-based psychotherapy, up to 20% of patients fail to respond to standard interventions. For these patients, trial-and-error combinations of multiple medications and electroconvulsive therapy are often required (Kennedy and Lam 2003; UK ECT Review Group 2003). For patients who remain severely depressed despite these aggressive approaches, new strategies are needed.