TMS or rTMS (repetitive transcranial magnetic stimulation) involves the use of an electromagnet applied to the head, it looks like a helmet, to induce a current in the brain. Unlike electroconvulsive therapy, it does not trigger a seizure, although in highenough doses it could.
TMS is currently being studied as a treatment for depression, obsessive-compulsive disorder, and migraines. It has also shown some efficacy in decreasing the auditory hallucinations associated with schizophrenia.
There have been case reports that TMS can cause a switch from depression to mania in people with bipolar disorder.