High-definition transcranial direct current stimulation enhances empathy-related cerebellar centrality in patients...

This double-blind randomized controlled trial aimed to investigate the effects of high-definition transcranial direct current stimulation (HD-tDCS) on degree centrality (DC) in the cerebellum and empathy in patients with schizophrenia.

Forty-five patients with schizophrenia were randomly assigned to either active stimulation group (n=24) or sham stimulation group (n=21). Both groups underwent HD-tDCS targeting the left dorsolateral prefrontal cortex (DLPFC). Resting-state fMRI scan, the Positive and Negative Syndrome Scale (PANSS) and Chinese version of the Interpersonal Reactivity Index (IRI-C) were applied at baseline and post-intervention. Degree centrality (DC) analysis and functional connectivity (FC) analysis were performed to identify changes in brain. Correlations between neural and behavioral alterations were examined.

After intervention, the active stimulation group showed a significant increase in DC in the right posterior cerebellum compared with their own baseline, whereas no such change was observed in the sham group. Exploratory analysis revealed enhanced FC between the right posterior cerebellum and right hippocampus in the active group post-intervention. Clinically, the active group exhibited significant reductions in total PANSS scores and positive symptom scores relative to baseline. A potential positive correlation was noted between the increased right posterior cerebellar DC and improved empathetic concern in the active group.

HD-tDCS over the left DLPFC emerges as a promising targeted intervention for schizophrenia, capable of modulating cerebellar functional integration (as reflected by improved DC) and alleviating clinical symptoms.