Vagus nerve stimulation for treatment-resistant depression: protocol for a pilot self-controlled trial

Background and objectives: Patients with treatment-resistant depression (TRD) show no improvement after treatment with a series of drugs. Previous reports have described positive effects of vagus nerve stimulation (VNS) on the emotional states of patients with epilepsy. VNS for TRD has not been explored in China. We will investigate the efficacy and safety of VNS for the treatment of TRD in a Chinese cohort. Design: A pilot self-controlled trial. Methods: The study population will comprise 10 consecutive patients with TRD admitted to Beijing Anding Hospital at Capital Medical University in Beijing, China. The patients will receive routine treatment supplemented with VNS starting at 2 weeks after surgery. Follow-up evaluations will be performed at 1, 2, 3, 6, and 12 months of nerve stimulation. Outcome measures: The primary outcome measure will be the change in the 17-item Hamilton Rating Scale for Depression (HAMD-17) total score from baseline to 12 months of nerve stimulation. The secondary outcome measures will include the proportion of patients who achieve ≥ 50% reduction from baseline in the HAMD-17 total score, complete remission rate, and the Quick Inventory of Depression Symptomatology-Self Report, 7-item Generalized Anxiety Disorder Scale, Global Assessment of Function, Clinical Global Impression-severity, Clinical Global Impression-improvement, Hamilton Rating Scale for Anxiety, Young Mania Rating Scale, Patient Health Questionaire-15, Sheehan Disability Scale, Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form, Perceived Deficits Questionnaire-Depression, Frequency, Intensity and Burden of Side Effects Rating, and Columbia-Suicide Severity Rating Scale scores. Discussion: The trial will provide objective data on the potential of the clinical implementation of VNS as a treatment for TRD in China. Ethics and dissemination: This study protocol was approved by the Institution Review Board of Beijing Anding Hospital of Capital Medical University in China (approval No. 201775FS-2) at October 2017. Design of the study was finished in August 2017, participant recruitment was started at December 2017, and data analysis will be completed until December 2021. The results of the study will be disseminated through presentations at peer-reviewed publications. Trial registration: This trial was registered in the Chinese Clinical Trial Registry with registration No. ChiCTR-ONC-174013430 (version 2.0) in November 2017.