Cortical inhibition and excitation in neuropsychiatric disorders using transcranial magnetic stimulation

Abstract

Transcranial magnetic stimulation (TMS) is a noninvasive brain stimulation technique used for the investigation of neurophysiological processes such as cortical inhibition, excitability, and plasticity. In the last 20 years, several studies have used TMS to study both cortical inhibition and excitation in psychiatric disorders. The purpose of this chapter is to focus on TMS studies which have enhanced our understanding of psychiatric illnesses such as schizophrenia (SCZ), obsessive-compulsive disorder (OCD), major depressive disorder (MDD), and bipolar disorder (BD). Research to date suggests that SCZ, OCD, MDD, and BD are characterized by deficits in cortical inhibition and by abnormalities in cortical excitability. This chapter discusses current TMS research and highlights the application of innovative neurophysiological techniques to provide a clear platform from which diagnostic and therapeutic procedures can be developed. Changes in cortical excitability and inhibition provide evidence that can advance our understanding of the pathophysiology of psychiatric disorders.