Overview
Transcranial magnetic stimulation (TMS) is a procedure that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of major depression. It's called a "noninvasive" procedure because it's done without using surgery or cutting the skin. Approved by the U.S. Food and Drug Administration (FDA), TMS usually is used only when other depression treatments haven't been effective.
​
The FDA also approved TMS for obsessive-compulsive disorder (OCD), migraines and to help people stop smoking when standard treatments haven't worked well. Research continues into other potential uses for TMS, including epilepsy.
When used for depression, OCD and to stop smoking, this treatment involves delivering repeated magnetic pulses, so it's called repetitive TMS or rTMS.
How It Works
During an rTMS session for depression, an electromagnetic coil is placed against the scalp of your head. This coil delivers magnetic pulses that stimulate nerve cells in the region of your brain involved in mood control and depression. It's thought to activate regions of the brain that have decreased activity during depression.
You also may hear the term "deep transcranial magnetic stimulation" or "deep TMS." The difference between rTMS and deep TMS has to do with the type of coil used. The deep TMS coil stimulates deeper and wider areas of the brain, compared with rTMS. Deep TMS coils have been FDA-approved for OCD and to stop smoking.
Although the biology of why TMS works isn't completely understood, the stimulation appears to affect how the brain is working. It seems to ease depression symptoms and improve mood.
There are different ways to perform TMS. Methods may change as experts learn more about the most effective ways to perform treatments.
Why It's Done
Depression is a treatable condition. But for some people, standard treatments aren't effective. Repetitive TMS may be used when standard treatments such as medicines, and talk therapy, known as psychotherapy, don't work.
TMS is sometimes used to treat OCD, migraines and to help people stop smoking after other treatments have not been successful.
How It's Done
Repetitive TMS is a noninvasive form of brain stimulation. Unlike vagus nerve stimulation or deep brain stimulation, rTMS does not require surgery or implanting electrodes. And, unlike electroconvulsive therapy (ECT), rTMS doesn't cause seizures or memory loss. It also doesn't require the use of anesthesia, which puts people in a sleep-like state.
Generally, rTMS is considered safe and well-tolerated. However, it can cause some side effects.
Common Side Effects
Side effects are generally mild to moderate and improve shortly after a session. Side effects decrease over time with more sessions.
​
Side effects may include:
-
Scalp discomfort and pain.
-
Headache.
-
Tingling, spasms or twitching of facial muscles.
-
Lightheadedness.
-
​
Your health care provider can adjust the level of stimulation to reduce symptoms. Or your provider may recommend that you take a pain medicine available without a prescription before the procedure. In some people who get frequent headaches or migraines, TMS triggers headaches, so treatments might need to be stopped.