Repetitive transcranial magnetic stimulation of the prefrontal cortex in depression

Transcranial magnetic stimulation is an interesting technique for non-invasively stimulating the brain in awake alert humans. It is a powerful research tool for examining brain behavior relationships. Additionally many researchers are investigating whether repeatedly applying TMS to specific regions over several days to weeks might have therapeutic effects. By far the largest amount of work has been done investigating whether daily applications of prefrontal TMS can improve the symptoms of major depression. We review the literature combining TMS with brain imaging, and then overview the clinical work done to date with TMS in depression. The literature to date suggests that daily prefrontal TMS for several weeks clearly has antidepressant effects, but much work remains to establish the effect sizes and improve the methods of delivery in order to improve its potential clinical utility. (C) 2009 Published by Elsevier Inc.