"ECT is carried out under general anaesthetic, and a strong muscle relaxant is administered to patients to prevent the violent muscle spasms that the treatment would otherwise cause. The patient is strapped on their back to a flat table which, in the event of a patient vomiting, can be spun upside down."In the presence of an anaesthetist and psychiatrist, electrodes are attached to the patient’s head and the electrical voltage is administered until the psychiatrist observes the patient’s toe twitch. This is a sign that the patient, despite the relaxant drugs, is convulsing. Up to 400 volts are used."
— Kierran HornerCustomer Service Centre UK Department of Health (November 2007)