The effect of transcutaneous auricular vagus nerve stimulation on treatment-resistant depression monitored by resting-state fMRI and MRS: The first case report

Abstract

Major depressive disorder (MDD) has a high prevalence rate and constitutes a leading cause of disability worldwide. Although there are various antidepressants available, approximately 35% of patients still can not achieve remission and progress to treatment-resistant depression (TRD) [ [1] Rush A.J. Trivedi M.H. Wisniewski S.R. Nierenberg A.A. Stewart J.W. Warden D. et al. Acute and longer–term outcomes in depressed outpatients requiring one or several treatment steps: a STAR*D report. Am J Psychiatry. 2006; 163: 1905-1917https://doi.org/10.1176/ajp.2006.163.11.1905 Crossref PubMed Scopus (0) Google Scholar ]. TRD is defined as an absence of response to at least two types of antidepressant drugs with adequate dose/duration [ [2] Sackeim H.A. The definition and meaning of treatment–resistant depression. J Clin Psychiatr. 2001; 62 ([PubMed: 11480879]): 10-17 PubMed Google Scholar ]. Invasive vagus nerve stimulation (VNS) is a neural-modulation therapy, which has been approved for TRD by Food and Drug Administration in 2005 (FDA). However, the surgery-related side effects have limited its application. The transcutaneous auricular VNS (taVNS) was therefore developed and has shown similar efficacy to invasive VNS in MDD patients [ 3 Conway C.R. Chibnall J.T. Gebara M.A. Price J.L. Snyder A.Z. Mintun M.A. et al. Association of cerebral metabolic activity changes with vagus nerve stimulation antidepressant response in treatment–resistant depression. Brain Stimul. 2013; 6: 788-797https://doi.org/10.1016/j.brs.2012.11.006 Abstract Full Text Full Text PDF PubMed Scopus (59) Google Scholar , 4 Hein E. Nowak M. Kiess O. Biermann T. Bayerlein K. Kornhuber J. et al. Auricular transcutaneous electrical nerve stimulation in depressed patients: a randomized controlled pilot study. J Neural Transm. 2013; 120: 821-827https://doi.org/10.1007/s00702-012-0908-6 Crossref PubMed Scopus (142) Google Scholar , 5 Fang J. Rong P. Hong Y. Fan Y. Liu J. Wang H. et al. Transcutaneous vagus nervestimulation modulates default mode network in major depressive disorder. Biol Psychiatry. 2016; 79: 266-273https://doi.org/10.1016/j.biopsych.2015.03.025 Abstract Full Text Full Text PDF PubMed Scopus (193) Google Scholar ]. However, whether taVNS is also effective for TRD remains unknown. Therefore, we are conducting a clinical trial to confirm effectiveness of taVNS and to explore the potential mechanism (trial number: ChiCTR-1800014277).