Transcutaneous vagus nerve stimulation modulates amygdala functional connectivity in patients with depression.

Author: Liu J1, Fang J2, Wang Z3, Rong P4, Hong Y2, Fan Y2, Wang X2, Park J5, Jin Y5, Liu C6, Zhu B7, Kong J8
Affiliation: <sup>1</sup>Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China; Department of Psychiatry, Massachusetts General Hospital / Harvard Medical School, Charlestown, MA 02129, USA. <sup>2</sup>Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China. <sup>3</sup>Department of Psychiatry, Massachusetts General Hospital / Harvard Medical School, Charlestown, MA 02129, USA; Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University, Guangzhou, China. <sup>4</sup>Institute of Acupuncture &amp; Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: rongpj@hotmail.com. <sup>5</sup>Department of Psychiatry, Massachusetts General Hospital / Harvard Medical School, Charlestown, MA 02129, USA. <sup>6</sup>Beijing Key Laboratory of Mental Disorders, Department of Radiology and Psychiatry, Beijing Anding Hospital, Capital Medical University, Beijing 100088, China. <sup>7</sup>Institute of Acupuncture &amp; Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China. <sup>8</sup>Department of Psychiatry, Massachusetts General Hospital / Harvard Medical School, Charlestown, MA 02129, USA. Electronic address: kongj@nmr.mgh.harvard.edu.
Conference/Journal: J Affect Disord.
Date published: 2016 Aug 11
Other: Volume ID: 205 , Pages: 319-326 , Special Notes: doi: 10.1016/j.jad.2016.08.003. [Epub ahead of print] , Word Count: 242


BACKGROUND: The amygdala is a key region in emotion processing, and studies have suggested that amygdala-frontal functional connectivity deficits could be modulated by antidepressants in major depressive disorder (MDD). Transcutaneous vagus nerve stimulation (tVNS), a non-invasive, peripheral neuromodulation method at the ear, has shown promising results in treating major depressive disorder (MDD) in several pilot studies. However, the neural mechanism underlying tVNS treatment of depression has not been fully investigated. In this study, we investigated how tVNS can modulate the amygdala-lateral prefrontal network resting state functional connectivity (rsFC) in mild or moderate major depressive disorder (MDD) patients.

METHODS: Forty-nine MDD patients were recruited and received tVNS or sham tVNS (stVNS) treatments for four weeks. Resting state fMRI scans were applied before and after treatments.

RESULTS: After 1 month of tVNS treatment, the 24-item Hamilton Depression Rating Scale (HAMD) scores were reduced significantly in the tVNS group as compared with the sham tVNS group. The rsFC in the tVNS group between the right amygdala and left dorsolateral prefrontal cortex was increased compared with sham tVNS. All the rsFC increases were also associated with HAMD reduction as well as reductions in the anxiety and retardation HAMD subscales.

CONCLUSIONS: tVNS can significantly modulate the amygdala-lateral prefrontal rsFC of MDD patients; our results provide insights into the brain mechanism of tVNS treatment for MDD patients.

Copyright © 2016 Elsevier B.V. All rights reserved.

KEYWORDS: Amygdala; Depression; Emotion; Resting-state functional connectivity; Transcutaneous vagus nerve stimulation

PMID: 27559632 DOI: 10.1016/j.jad.2016.08.003