Magnetic Seizure Therapy (MST) for Severe Mood Disorder

The purpose of this study is to compare the clinical efficacy and side effects of Magnetic Seizure Therapy (MST) and Electroconvulsive Therapy (ECT) in patients currently experiencing a major depressive episode in the context of either unipolar or bipolar depression. ECT is known to be highly effective in treating depression, but it can have some adverse cognitive side effects. MST is a new form of convulsive therapy that is being developed as a means of improving the side effect profile of ECT so that more patients may benefit without suffering significant detrimental effects on cognition. Both ECT and MST cause a seizure, but they do so in different ways. In ECT, an electrical stimulator is used to pass an electrical current between two electrodes placed on the person's head, which causes some electricity to go through the brain and cause a seizure. In MST, a magnetic stimulator is used to pass a magnetic field to the brain, which then creates a small electrical field in the brain that causes a seizure. In addition to the treatment sessions, this study will involve a number of assessments at different timepoints that are used to evaluate the person's antidepressant response and the physical and cognitive side effects of treatment.