Noninvasive direct current stimulation for schizophrenia: a review

To provide an update of recent studies describing the effects of transcranial direct current stimulation (tDCS) on patients with schizophrenia, with particular focus on auditory verbal hallucinations (AVH), cognitive deficits, and negative symptoms.

As a low-cost, easy-to-use neuromodulation technique, tDCS may have clinical implications for those suffering from treatment-persistent AVH, negative symptoms, and cognitive symptoms in schizophrenia. Over the past decade, tDCS has shown no effects for negative symptoms, except when used at a high frequency of sessions, and inconclusive results for AVH and cognitive symptoms. The treatment has little to no adverse effects.

The studies reviewed here support the need for further investigation and empirical data regarding the use of tDCS. The underlying mechanisms of tDCS as well as the most effective stimulation parameters must be better understood. Findings support the need for increased duration and frequency of tDCS sessions. One of the next steps is the investigation of effects of concomitant nonpharmacological treatments with tDCS.