High-definition tDCS regulate the prefrontal-limbic-striatal connectivity and reduce depression in youth with first-episode depression.

BACKGROUND

Transcranial direct current stimulation (tDCS) has emerged as a promising approach to alleviate depressive symptoms in depression. However, the underlying therapeutic mechanisms remain largely unexplored. This study aims to investigate the improvement in symptoms and changes in resting-state brain activities in youth with first-episode depression (FED) before and after a two-week high-definition tDCS (HD-tDCS) intervention.

METHOD: This study included 18 young adults with FED and 14 healthy controls. Participants received ten sessions of HD-tDCS (2 mA, 20 min, stimulation target: left dorsolateral prefrontal) administered once a day over a two-week period. Clinical assessment and resting-state magnetic resonance imaging were conducted on all participants at baseline and post-treatment. We used voxel-wise functional connectivity (FC) analysis to explore changes in FC within emotion-related regions in the FED group following HD-tDCS and explored potential correlations between these FC alterations and improvements in depressive symptoms.

RESULTS

The FED group exhibited significant improvement in depression and anxiety scores after treatment. The FC in the prefrontal-limbic-striatal system was decreased between AMYG, HIP, NAcc as well as FG and the prefrontal cortex. The reduction in depression severity was significantly positively correlated with decreased FC values between right FG and right middle frontal gyrus.

CONCLUSION

This study suggests that tDCS may be an effective intervention for young adults with FED. The improvement in depressive symptoms induced by tDCS was associated with modulation of brain connectivity in cortical and subcortical regions within the prefrontal-limbic-striatal system. Our study provides novel neurobiological evidence for the treatment of depression with tDCS.