The efficacy and safety of transcutaneous auricular vagus nerve stimulation in the treatment of depressive disorder: A systematic review and meta-analysis of randomized controlled trials Author: Chaoren Tan1, Meng Qiao2, Yue Ma3, Yi Luo3, Jiliang Fang3, Yongsheng Yang4 Affiliation: <sup>1</sup> Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Science, 100700 Beijing, China. <sup>2</sup> Institute of Basic Research in Clinical Medicine, China Academy of Chinese Medical Sciences, 100700 Beijing, China. <sup>3</sup> Guang&#x27;anmen Hospital, China Academy of Chinese Medical Sciences, 100053 Beijing, China. <sup>4</sup> Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Science, 100700 Beijing, China. Electronic address: yysh1950@sina.com. Conference/Journal: J Affect Disord Date published: 2023 May 23 Other: Special Notes: doi: 10.1016/j.jad.2023.05.048. , Word Count: 252 Background: Transcutaneous auricular vagus nerve stimulation (taVNS) is used for treating depression but the efficacy and safety have not been well assessed. This study was conducted to evaluate the efficacy and safety of taVNS in depression. Methods: The retrieval databases included English databases of PubMed, Web of Science, Embase, the Cochrane Library and PsycINFO, and Chinese databases of CNKI, Wanfang, VIP and Sino Med, and the retrieval period was from their inception to November 10, 2022. The clinical trial registers (ClinicalTrials.gov and Chinese Clinical Trial Registry) were also searched. Standardized mean difference and the risk ratio were used as the effect indicator and the effect size was represented by the 95 % confidence interval. Revised Cochrane risk-of-bias tool for randomized trials and the Grades of Recommendation, Assessment, Development and Evaluation system were used to assess the risk of bias and quality of evidence respectively. Results: Totally, 12 studies of 838 participants were included. taVNS could significantly improve depression and reduce Hamilton Depression Scale scores. Low to very low evidence showed that taVNS had higher response rates than sham-taVMS and comparable response rates compared to antidepressants (ATD) and that taVNS combined with ATD had comparable efficacy to ATD with fewer side effects. Limitations: The number of studies in subgroups was small and the evidence quality was low to very low. Conclusions: taVNS is an effective and safe method for alleviating depression scores and had a comparable response rate to ATD. Keywords: Depression; Randomized controlled trial; Transcutaneous auricular vagus nerve stimulation; Vagus nerve stimulation; meta-analysis. PMID: 37230264 DOI: 10.1016/j.jad.2023.05.048