Even before the movie "One Flew Over the Cuckoo's Nest" was released more than 30 years ago, electroconvulsive therapy-or shock therapy-was falling out of favor as a cure for depression. And once the movie was released, people had a hard time seeing the treatment as anything but cruel and inhumane. But in fact, many psychiatrists believe that it's a safe, effective form of treatment for severe depression and other types of mental illness, which is probably why it's now enjoying a resurgence in popularity.

What is shock therapy exactly? The procedure, first used some 70 years ago in Europe, involves passing an electrical current through the brain to induce seizures. The seizures, lasting anywhere from half a minute to a couple of minutes, apparently "rebalance" the chemicals in the brain to alleviate the symptoms of depression.

Because the procedure can be uncomfortable, patients undergoing shock therapy first receive a general anesthetic as well as muscle relaxants. The therapy is not performed unless the patient also undergoes a battery of psychiatric, medical and neurological tests first, as well as a blood analysis. Treatments are administered two or three times a week until all the depressive symptoms are gone. Typically, patients experience some memory loss after the procedure, but most often it returns within a few days. Nausea, muscle aches and headaches also are not uncommon.

While shock therapy can be extremely effective, it only works for about three-quarters of those who have it, many of whom will relapse. But a recent study of 319 shock-therapy patients at Wake Forest University revealed that shock therapy combined with antidepressants is more effective than shock therapy on its own, and results in less memory loss than shock therapy on its own.

Sources: Johns Hopkins Medicine, www.hopkinshospital.org, Wake Forest University, www1.wfubmc.edu.