Transcranial magnetic stimulation (TMS) is a noninvasive procedure that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of depression. TMS is typically used when other depression treatments haven’t been effective.

TMS does not involve surgery or insertion of intravenous lines or anything else put into your body. It also does not require any anesthesia or sedation. 

TMS uses a small electromagnetic coil controlled by a computer program to deliver short, powerful bursts of magnetic energy-focused precisely on the left side of the brain’s frontal cortex. The TMS magnetic fields are the same type and strength as those produced by a magnetic resonance imaging (MRI) machine.

A treatment coil is applied to the head above the targeted area of the brain, called the prefrontal cortex. This part of the brain is involved with mood regulation. TMS magnetic fields do not directly affect the whole brain; they only reach about 2-3 centimeters into the brain directly beneath the treatment coil. As TMS magnetic fields move into the brain, they produce very small electrical currents. The electrical currents activate cells within the brain, which are thought to release neurotransmitters.

The typical initial treatment course consists of five treatments per week over a four to six-week period, for an average of 20-30 total treatments. Additional treatments may be used to maintain optimal antidepressant benefits, but a frequency schedule for “maintenance” TMS treatments has not yet been established.  The average treatment time is about 20 minutes and the office visit lasts less than an hour.