Background Depression is the most common form of mental disorder in community and
health care settings and current treatments are far from satisfactory. Vagus nerve stimulation
(VNS) is a Food and Drug Administration approved somatic treatment for treatment-resistant
depression. However, the involvement of surgery has limited VNS only to patients who have
failed to respond to multiple treatment options. Transcutaneous VNS (tVNS) is a relatively
new, noninvasive VNS method based on the rationale that there is afferent/efferent vagus …