HD-tDCS for Hallucinations

One in three patients with schizophrenia experiences hallucinations that are refractory to conventional pharmacotherapy. For refractory auditory hallucinations, transcranial direct current stimulation -tDCS- has been proposed as a novel therapeutic approach. Although promising beneficial effects on auditory hallucinations have been found by targeting the left frontal and temporoparietal cortex, the high variability observed in clinical response leaves much room for optimizing stimulation parameters. For instance, options should go beyond the left temporoparietal junction as a unique and single target of hallucinations, taking into account the personalization of the targeting based on the actual brain networks involved in hallucinations, including those beyond the auditory modality, as well as multimodal hallucinations. The present study will take advantage of recent technological developments to propose a personalized therapeutic strategy to alleviate hallucinations in schizophrenia. This will involve: * the simultaneous targeting of multiple brain regions with High-Definition (HD)-tDCS, which is known for its precise and longer-lasting effects compared to conventional tDCS. * and the fMRI-capture of hallucinations, using a precise and reliable data-driven approach to identify the functional brain networks recruited during hallucinations. The aim of the study is to assess whether repeated sessions of HD-tDCS guided using the fMRI capture of hallucinations can reduce multimodal hallucinations in patients with schizophrenia, compared to sham sessions of HD-tDCS.