Durability of symptomatic responses obtained with adjunctive vagus nerve stimulation in treatment-resistant depression
Received 1 December 2018
Accepted for publication 22 January 2019
Published 13 February 2019 Volume 2019:15 Pages 457—468
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 3
Editor who approved publication: Dr Roger Pinder
Arun Kumar,1 Mark T Bunker,1 Scott T Aaronson,2 Charles R Conway,3 Anthony J Rothschild,4,5 Giacomo Mordenti,6 Augustus J Rush7,8
1LivaNova USA PLC, Houston, TX, USA; 2Department of Clinical Research, Sheppard Pratt Health System, Baltimore, MD, USA; 3Department of Psychiatry, Washington University School of Medicine in St Louis, St Louis, MO, USA; 4Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, USA; 5Department of Psychiatry, UMass Memorial Medical Center, Worcester, MA, USA; 6LivaNova PLC, London, UK; 7Department of Psychiatry and Behavioral Sciences, National University of Singapore, Singapore; 8Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, NC, USA
Objective: To compare the durations of response achieved with adjunctive vagus nerve stimulation (VNS + TAU) vs treatment as usual (TAU) alone in treatment-resistant depression (TRD) over a 5-year period in the TRD registry.
Materials and methods: Data from 271 participants on TAU and 328 participants on VNS + TAU were analyzed. Response was defined as ≥50% decrease in baseline Montgomery–Åsberg Depression Rating Scale (MADRS) score at postbaseline visit and was considered retained until the decrease was <40%. MADRS was obtained quarterly in year 1 and biannually thereafter. Time-to-events were estimated using Kaplan–Meier method and compared using log-rank test. HR was estimated using Cox proportion hazard model.
Results: In the VNS + TAU arm, 62.5% (205/328) of participants had a first response over 5 years compared with 39.9% (108/271) in TAU. The time to first response was significantly shorter for VNS + TAU than for TAU (P<0.01). For responders in the first year, median time to relapse from first response was 10.1 months (Q1=4.2, Q3=31.5) for VNS + TAU vs 7.3 months (Q1=3.1, Q3=17.6) for TAU (P<0.01). HR=0.6 (95% CI: 0.4, 0.9) revealed a significantly lower chance for relapse in VNS + TAU. Probability of retaining first response for a year was 0.39 (0.27, 0.51) for TAU and 0.47 (0.38, 0.56) for VNS + TAU. Timing of the onset of the response did not impact the durability of the response.
Conclusion: VNS therapy added to TAU in severe TRD leads to rapid onset and higher likelihood of response, and a greater durability of the response as compared to TAU alone.
Keywords: depressive disorder, treatment-resistant depression, vagus nerve stimulation, longitudinal study, durability of response
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]