Transcranial Magnetic Stimulation (TMS) is a non-invasive treatment used to stimulate small regions of the brain. During a TMS procedure, a magnetic field generator, or coil, is placed near the head. The coil produces and sends a therapeutic electromagnetic pulse to a specific region of the brain.
When people become depressed, their right frontal lobe, which is responsible for feelings of anxiety and avoidance behaviour can become more active, while the left frontal lobe, the source of feelings of optimism and approach behaviours usually becomes less active.
When using TMS to treat depression, doctors send either a high frequency pulse to the left frontal lobe to increase activity, or a low frequency pulse to the right frontal lobe to decrease activity.