Psychiatric application of transcranial direct current stimulation (tDCS)

As neuroscientific backgrounds about pathophysiology of psychiatric diseases have been accumulated, brain stimulation has emerged as an important mechanism-based treatment modality. Transcranial direct current stimulation (tDCS) is among the most noninvasive, simple, and relatively focal methods of brain stimulation. tDCS has a unique mechanism of modulating cortical excitability in a polarity-specific manner without eliciting action potentials, also demonstrates lasting after-effects. tDCS has been regarded as a promising tool in research on memory and learning and has been investigated as a potentially therapeutic modality in clinical trials for depression and craving-related conditions. This article reviews application procedures, safety concerns, and the possible modes of action of tDCS. Basic researches on and clinical trials of tDCS in psychiatry are introduced primarily focused on the treatment of depression. Although evidence remains limited, tDCS seems to offer promising neuromodulatory techniques compared to other stimulatory methods in psychiatry and further studies are warranted.