Transcranial Magnetic Stimulation (TMS) for Major Depressive Disorder-Modus Operandi!

Background: Transcranial magnetic stimulation (TMS) is effective in the management of treatment resistant major depressive disorder (MDD) and has recently become widely available. Our aim was to explore the literature for evidence of the mechanism of action.

Method: We examined our own accumulating TMS library, the reference lists of all available papers and used a search engine to collect information. We collated and examined this information under relevant heading.

Results: TMS produces a large number of physiological changes including site of stimulation neurochemical, brain wave and blood flow effects, and distant structure effects including neurotransmitter effects and volume increase. TMS also corrects generalized and local functional connectivity (FC) abnormalities which are a feature of MDD.

Conclusion: TMS produces a range of physiological changes. It is unclear which of these underpin its antidepressant. It is likely more than one work synergistically to this end-almost certainly the capacity to correct MDD induced FC abnormalities makes a strong antidepressant contribution.