Effects of high-definition transcranial direct current stimulation (HD-tDCS) on resting brain functional connectivity in schizophrenia patients with persistent auditory verbal hallucinations.

High-definition transcranial Direct Current Stimulation (HD-tDCS) is an emerging neuromodulation technique for treating auditory verbal hallucinations (AVH) in schizophrenia (SZ) that do not respond adequately to psychotropic treatments. We are unaware of any functional Magnetic Resonance Imaging (fMRI) study examining the neural effect of HD-tDCS on AVH in SZ. In this study, we examined the effect of MRI-neuronavigated HD-tDCS on functional brain connectivity using fMRI in SZ patients (N = 34) with persistent AVH. HD-tDCS was delivered in a double-blind, randomized, parallel-arm, sham-controlled design (5 days of twice daily, 20-minute sessions). The resting-state fMRI data was acquired using a 3 T scanner. Active HD-tDCS treatment, in comparison to the sham, resulted in significant changes in the resting-state functional connectivity involving Heschl's gyrus, temporoparietal junction, caudate nucleus, precuneus, lateral occipital cortex, and hippocampus. Our study shows that HD-tDCS causes brain connectivity changes in regions implicated in AVH pathogenesis in SZ.