A technique, used mainly in treating severe DEPRESSION, of producing behavioural changes by passing an electrical current briefly through a patient's brain. The technique causes muscular convulsions and renders the patient unconscious. It is claimed that the patient's depression can often be eased in this way but nobody knows why, nor whether there are any permanent long-term side effects. Nowadays the patient is usually given a sedative and a muscle-relaxing drug before ECT to reduce the dangers of physical damage occurring. Commonly known as 'shock treatment' and considered barbaric by many psychologists.