Many people begin to notice an improvement in their symptoms after two or three treatments with electroconvulsive therapy. Full improvement may take longer. Response to antidepressant medications, in comparison, can take several weeks or more.

No one knows for certain how ECT helps treat severe depression and other mental illnesses. What is known, though, is that many chemical aspects of brain function are changed during and after seizure activity. These chemical changes may build upon one another, somehow reducing symptoms of severe depression or other mental illnesses. That's why ECT is most effective in people who receive a full course of multiple treatments.

Even after your symptoms improve, you'll still need ongoing treatment to prevent a recurrence. Known as maintenance therapy, that ongoing treatment doesn't have to be ECT, but it can be. More often, it includes antidepressants or other medications, or psychological counseling (psychotherapy).

Oct. 25, 2012