Electroconvulsive therapy, illustration

Illustration of a patient undergoing electroconvulsive therapy (ECT). The electrodes placed at the right temple and near the top of the head will deliver an electrical current that will induce a seizure in the patient's brain. This right unilateral placement of the electrodes may lessen memory loss compared to bilateral (at both temples) electrode placement. Brain activity is monitored by the electrodes placed above the forehead. ECT is given under a general anaesthetic and the mouth guard prevents the patient from biting their tongue. ECT is used to treat some severe mental illnesses when other treatments haven't helped. It is effective in some cases, although why it works is not fully understood. Use of the treatment can be controversial, especially as in the past it was used while patients were still conscious and often without their consent., by JOSE ANTONIO PEÑAS/SCIENCE PHOTO LIBRARY