Electroconvulsive therapy(ECT) is a treatment for depression. It's not absolutely clear how it works. A side effect of ECT is memory loss. ECT often works very quickly, greatly lifting your depression. However, it doesn't appear to stop depression coming back in the future. This treatment is only considered if you're severely depressed or if treatment with medicines hasn't worked for you. ECT is always given in hospital under general anaesthesia, which means you will be asleep during the procedure and feel no pain. It works by passing an electric current through the brain and causing a seizure. People tend to have ECT sessions twice/week for 6-12 sessions.
Attribution: BUPA