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. . Typically, 70 to 120 volts of pulsed electricity are applied externally to the patient's head resulting in approximately 800 milliamperes of direct current passed through the brain, for 100 milliseconds to 6 seconds duration, either from temple to temple (bilateral ECT) or from front to back of one side of the head (unilateral ECT). 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 were originally placed in the Class III category by the United States Food and Drug Administration (FDA) since 1976. They were re-classified as Class II devices, for treatment of catatonia, major depressive disorder, and bipolar disorder, in 2018.