Brunelin J, Mondino M, Gassab L et al.
Centre Hospitalier Le Vinatier, Bron, France.
Am J Psychiatry 2012;169:719–24.
Editor’s note: Auditory verbal hallucinations (AVHs) are common, often treatment-resistant, symptoms in schizophrenia. Studies have demonstrated that repetitive transcranial magnetic stimulation (rTMS), a non-invasive neurostimulation technique, is effective in the treatment of AVHs, probably acting by reducing excitability in the left temporoparietal cortices. However, study results are inconsistent, and there is agreement on the fact that technical approaches must be improved. Given that the dorsolateral prefrontal cortex is hypoactive and the temporoparietal cortex hyperactive during AVHs in patients with schizophrenia, the authors of the present study investigated the effect of transcranial direct-current stimulation (tDCS), a new non-invasive neurostimulation technique that is increasingly being used in neurology and psychiatry (Brain Res Rev 2007;56:346–61). With this technique, neuronal excitability is increased near the placement of the anode (which is analogous to high-frequency rTMS) and reduced near the cathode (analogous to low-frequency rTMS). When applied to a two-node cortical system, tDCS can increase tissue activity in one area and reduce it in another.