Transcranial Electrical Stimulation: Clinical Implication and Practice for Treatment of Psychiatric Illness

Abstract

Brain electrical stimulation, particularly non-invasive brain stimulation (NIBS) techniques such as transcranial electrical stimulation (tES), have emerged as a promising treatment for various psychiatric disorders, including depression, anxiety, and post-traumatic stress disorder. tES techniques, such as transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS), are cost-effective and safe interventions that are designed to affect neuronal circuits in the brain using various modalities. Although tES has shown effectiveness in the treatment of psychiatric disorders, there is a lack of comprehensive papers that consider its clinical implications. Therefore, this review aims to evaluate the clinical implications of tES and provide practical guidance for the treatment of psychiatric illnesses. Moreover, this review provides an overview of tES techniques and their mechanisms of action and summarizes recent clinical studies that have examined the use of tES for psychiatric disorders.

Keywords: Transcranial alternating current stimulation; Transcranial direct current stimulation; Transcranial electrical stimulation; Transcranial random noise stimulation.

Fig. 1

Various types for transcranial electrical stimulation (tES). (A) Transcranial direct current stimulation (tDCS) delivers direct and monopolar current which fades in/fades out at the beginning and end of the stimulation until the desired intensity is achieved. (B) Transcranial alternating current stimulation (tACS) delivers biphasic sinusoidal current alternates between positive and negative voltages and enables entrainment of brains’ endogenous oscillations. (C) Transcranial random noise stimulation (tRNS) delivers fluctuating currents within a specific range.

Fig. 2

Mechanism of transcranial direct current stimulation (tDCS).

Fig. 3

Multichannel transcranial direct current stimulation (tDCS) mon-tages. (A) Multichannel tDCS device. Image courtesy of Soterix Medical, Inc. (www.soterixmedical.com). (B) Solid line circles represent anodal electrodes and dotted line circles represent reference electrodes.