Transcranial direct current stimulation (tDCS) is a non-invasive electrical neuromodulation technique that is used as potential treatment for neurological disorders. These disorders include depression, strokes, epilepsy, and Parkinson's.

Two electrodes (anodes and cathodes) are placed on the scalp to produce an electric current. Anodal tDCS excites the target region, whereas cathodal tDCS decreases excitability which produces a type of polarity.

Although some research shows that tDCS is effective in certain treatments, other research also indicates wide variability.