Treatments for Major Depression Electroconvulsive Therapy Electroconvulsive therapy (ECT) is simultaneously the oldest, most effective, most feared, and most effective somatic (non-psychotherapy) treatment for major depression. As early as the 1930s, it became apparent that patients with severe mental illness would often have improvement in their symptoms after suffering a series of epileptic seizures. These observations led to studies, initially with chemicals, and then mor