Electroconvulsive therapy (ECT) is a very effective and generally safe treatment for depression and some other health conditions that uses electricity to trigger a seizure. It is most often done in a hospital while under anesthesia and is pain-free. The patient receives medicine to prevent the seizure from spreading throughout the body. Patients generally waken several minutes after ECT and do not remember the treatment.
Transcranial Magnetic Stimulation (TMS) can be targeted to a specific site in the brain. TMS uses a magnet instead of an electrical current to activate the brain. It was first developed in 1985 and has been studied as a possible treatment for depression, psychosis and other disorders since the mid-1990s. In 2008, TMS was approved for use by the Food and Drug Administration as a treatment for major depression for patients who have not responded to at least one antidepressant medication.
Source: National Institute of Mental Health