Transcranial direct current stimulation for refractory auditory hallucinations in schizophrenia.

Some patients with schizophrenia may suffer from continuous or severe auditory hallucinations that are refractory to antipsychotic drugs, including clozapine. Such patients may benefit from a short trial of once- to twice-daily transcranial direct current stimulation (tDCS) with the cathode placed over the left temporoparietal cortex and the anode over the left dorsolateral prefrontal cortex; negative, cognitive, and other symptoms, if present, may also improve. At present, the case for tDCS treatment of refractory auditory hallucinations rests on 1 well-conducted randomized, sham tDCS-controlled trial and several carefully documented and instructive case reports. Benefits with up to 3 years of maintenance tDCS have also been described. In patients with refractory auditory hallucinations, tDCS has been delivered at 1- to 3-mA current intensity during 20-30 minutes in once- to twice-daily sessions for up to 3 years with no apparent adverse effects. Transcranial direct current stimulation therefore appears to be a promising noninvasive brain stimulation technique for patients with antipsychotic-refractory auditory hallucinations.