Modelling Electric Field Distribution in Transcranial Direct Current Stimulation Targeting Auditory Verbal Hallucinations in People with Schizophrenia: A SimNIBS Simulation Study

Transcranial direct current stimulation (tDCS) as a potential alternate or add-on treatment for auditory verbal hallucinations (AVH) in people with schizophrenia (SCZ) exhibits variability in terms of its therapeutic effects, such as reducing positive symptoms. This study explores the utility of a non-invasive brain stimulation software called SimNIBS simulation software to investigate the role of individual anatomical differences in potentially influencing the effectiveness of tDCS treatment. Magnetic resonance imaging (MRI) data was collected from 12 participants with SCZ and a history of AVHs to construct head models, which were segmented and adjusted manually. The SimNIBS graphical user interface was used to mirror actual tDCS electrode size and placements for individual head models. The simulation modelled variability of the electric field (EF) depth and distribution in regions of interest across participants. The use of SimNIBS as a tool to model E-field contributions to our understanding of the effectiveness of tDCS treatment, while also demonstrating the importance of individualized treatment protocols.