Electroconvulsive Therapy (ECT)
Electroconvulsive therapy (ECT), formerly known as electroshock therapy, is a psychiatric treatment in which seizures are electrically induced in patients to provide relief from mental disorders. The ECT procedure was first conducted in 1938 and rapidly replaced less safe and effective forms of biological treatments in use at the time. ECT is often used with informed consent as a safe and effective intervention for major depressive disorder, mania, and catatonia. ECT machines have been placed in the Class III category by the United States Food and Drug Administration (FDA) since 1976.
A round of ECT is effective for about 50% of people with treatment-resistant major depressive disorder, whether it is unipolar or bipolar. Follow-up treatment is still poorly studied, but about half of people who respond relapse within 12 months. Aside from effects in the brain, the general physical risks of ECT are similar to those of brief general anesthesia. Immediately following treatment, the most common adverse effects are confusion and transient memory loss. Among treatments for severely depressed pregnant women ECT is one of the least harmful to the gestating fetus.
A usual course of ECT involves multiple administrations, typically given two or three times per week until the patient is no longer suffering symptoms. ECT is administered under anesthetic with a muscle relaxant. Electroconvulsive therapy can differ in its application in three ways: electrode placement, frequency of treatments, and the electrical waveform of the stimulus. These three forms of application have significant differences in both adverse side effects and symptom remission. Placement can be bilateral, in which the electric current is passed across the whole brain, or unilateral, in which the current is passed across one hemisphere of the brain. Bilateral placement seems to have greater efficacy than unilateral, but also carries greater risk of memory loss. After treatment, drug therapy is usually continued, and some patients receive maintenance ECT.
ECT appears to work in the short term via an anticonvulsant effect mostly in the frontal lobes, and longer term via neurotrophic effects primarily in the medial temporal lobe.