Objectives: Major depressive disorder is one of the most common mental illnesses. This study aims to investigate the effectiveness of transcutaneous auricular vagus nerve stimulation compared with the effectiveness of citalopram, a commonly used antidepressant, in patients with depression.
Material and methods: A total of 107 male and female patients with major depressive disorder (55 in the taVNS group and 52 in the citalopram group) were enrolled in a prospective 12-week, single-blind, comparative effectiveness trial. Participants were recruited from the outpatient departments of three hospitals in China.
Participants were randomly assigned to either transcutaneous auricular vagus nerve stimulation treatments (eight weeks, twice per day, with an additional four-week follow-up) or citalopram treatment (12 weeks, 40 mg/d). The primary outcome was the 17-item Hamilton Depression Rating Scale (HAM-D17) measured every two weeks by trained interviewers blinded to the treatment assignment. The secondary end points included the 14-item Hamilton Anxiety Scale and peripheral blood biochemical indexes.
Results: The HAM-D17 scores were reduced in both treatment groups; however, there was no significant group-by-time interaction (95% CI: -0.07 to 0.15, p = 0.79). Nevertheless, we found that transcutaneous auricular vagus nerve stimulation produced a significantly higher remission rate at week four and week six than citalopram. Both treatments were associated with significant changes in the peripheral blood levels of 5-hydroxytryptamine, dopamine, γ-aminobutyric acid, and noradrenaline, but there was no significant difference between the two groups.
Conclusion: Transcutaneous auricular vagus nerve stimulation resulted in symptom improvement similar to that of citalopram; thus, transcutaneous auricular vagus nerve stimulation should be considered as a therapeutic option in the multidisciplinary management of major depressive disorder.