tVNS (Transcutaneous Vagal Nerve Stimulation) for Depression: Improves Default Mode Network

statue of Kuan Yin — Ancient Medicine Made Modern

I have done some tVNS similar to that described here in the clinic. The stress (HRV) results are consistent within a patient, but not across patients groups. I’m not sure why, but I’m working on it.

Biol Psychiatry. 2016 Feb 15;79(4):266-73. doi: 10.1016/j.biopsych.2015.03.025. Epub 2015 Apr 2.

Transcutaneous Vagus Nerve Stimulation Modulates Default Mode Network in Major Depressive Disorder.

Fang J¹, Rong P², Hong Y³, Fan Y³, Liu J³, Wang H³, Zhang G³, Chen X⁴, Shi S³, Wang L⁵, Liu R⁶, Hwang J⁴, Li Z⁷, Tao J⁸, Wang Y⁹, Zhu B⁶, Kong J

Abstract

BACKGROUND:

Depression is the most common form of mental disorder in community and health care settings and current treatments are far from satisfactory. Vagus nerve stimulation (VNS) is a Food and Drug Administration approved somatic treatment for treatment-resistant depression. However, the involvement of surgery has limited VNS only to patients who have failed to respond to multiple treatment options. Transcutaneous VNS (tVNS) is a relatively new, noninvasive VNS method based on the rationale that there is afferent/efferent vagus nerve distribution on the surface of the ear. The safe and low-cost characteristics of tVNS have the potential to significantly expand the clinical application of VNS.

METHODS:

In this study, we investigated how tVNS can modulate the default mode network (DMN) functional connectivity (FC) in mild or moderate major depressive disorder (MDD) patients. Forty-nine MDD patients were recruited and received tVNS or sham tVNS (stVNS) treatments.

RESULTS:

Thirty-four patients completed the study and were included in data analysis. After 1 month of tVNS treatment, the 24-item Hamilton Depression Rating Scale score reduced significantly in the tVNS group as compared with the stVNS group. The FC between the DMN and anterior insula and parahippocampus decreased; the FC between the DMN and precuneus and orbital prefrontal cortex increased compared with stVNS. All these FC increases are also associated with 24-item Hamilton Depression Rating Scale reduction.

CONCLUSIONS:

tVNS can significantly modulate the DMN FC of MDD patients; our results provide insights to elucidate the brain mechanism of tVNS treatment for MDD patients.