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

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 an FDA-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, non-invasive 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. Result 34 patients completed the study and were included in data analysis. After one month of tVNS treatment, the 24-item Hamilton Depression Rating Scale (HAMD) score reduced significantly in the tVNS group as compared to 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 to stVNS. All these FC increases are also associated with HAMD 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.

Effect of transcutaneous auricular vagus nerve stimulation on major depressive disorder: A nonrandomized controlled pilot study

“…Some patients (n = 49) were also invited to participate in an fMRI study at baseline and after 4 weeks of treatment to investigate the brain resting state functional connectivity changes before and after one month of taVNS as compared to sham taVNS. Please see the original publication for more details (Fang et al, 2015). The present study will focus on the clinical outcomes of a 12-week treatment of the multiple-center clinical trial, which was not reported in the previous brain imaging study.…”

Transcutaneous Auricular Vague Nerve Stimulation: A Promising Alternative Therapy for Insomnia Disorder

“…In order to overcome the disadvantages of classic VNS, we developed taVNS. And we accidently found that taVNS could improve patients sleeping conditions in depressed patients [29] and in epilepsy patients [30] during our clinical studies process. In addition, taVNS can trigger melatonin secretion, which may be one of the key mechanisms of improving sleeping conditions in patients [31].…”

“…Auricular acupuncture (AA), which is often recommended as treatment for insomnia [20], inspired us to invent transcutaneous auricular vagus nerve stimulation (taVNS) years ago (Figure 4). We accidently found that taVNS could improve patients sleeping conditions in depressed patients [29] and in epilepsy patients [30] during our clinical studies process. We considered that taVNS is a promising alternative therapy for insomnia disorder with a bright future.…”

Therapeutic implications of the choroid plexus–cerebrospinal fluid interface in neuropsychiatric disorders

“…Evidence for the role of a nervous component in neuropsychiatry was shown by the use of vagus nerve stimulation (VNS) for treatment-resistant mood disorders such as depression (Albert et al, 2015). VNS is an FDA approved treatment that improves depressive symptoms (Albert et al, 2015;Fang et al, 2015;Shiozawa et al, 2014). Hypofunction of the parasympathetic vagus nerve was also shown to be involved in the pathophysiology of schizophrenia (Bar et al, 2008(Bar et al, , 2005(Bar et al, , 2012Malaspina et al, 1997;Boettger et al, 2006;Ostermann et al, 2013).…”