A controversial but sometimes rapidly effective treatment for cases of severe DEPRESSION, particularly where psychotic features are present (see PSYCHOSIS), or in high-risk patients such as suicidal or post-partum patients. ECT is only indicated after antidepressants have been tried and found to be ineffective; the full procedure of treatment should be explained to the patient, whose informed consent (or the consent of the appointed deputy for an individual who does not have CAPACITY) must be obtained.

The procedure is performed under a general anaesthetic. Depending on the side of the patient's dominance, either unilateral (on the side of the non-dominant hemisphere of the BRAIN) or bilateral (if dominance is uncertain, e.g. in left-handed people) positioning of electrodes is used. Unilateral ECT has the advantage of being associated with less AMNESIA. When the current passes, the muscles will contract for approximately 10 seconds, with further tonic spasms lasting up to a minute. The patient should then be put in the COMA or recovery position and observed until fully conscious.