Effect of transcutaneous auricular vagus nerve stimulation on major depressive disorder: A nonrandomized controlled pilot study

Abstract

Background Depression presents a significant burden to both patients and society. One treatment that has emerged is vagus nerve stimulation (VNS), an FDA-approved physical treatment for depressive disorders. However, the application of this intervention has been limited by the involvement of surgery and potential side effects. The aim of this study is to explore the effectiveness of stimulating the superficial branches of the vagus nerve as a solo treatment for MDD. Methods This is a nonrandomized, controlled study. The first cohort of patients (n = 91) only received transcutaneous auricular VNS (taVNS) for 12 weeks. In the second cohort (n = 69), patients first received 4 weeks of sham taVNS followed by 8 weeks of taVNS. All treatments were self-administered by the patients at home after they received training from the hospitals. The primary outcome measurement was the 24-item Hamilton Depression Rating Scale measured at weeks 0, 4, 8, and 12. Data analysis included a timelag analysis comparing 1) real and sham taVNS groups at week 4; 2) the real taVNS group at week 4 vs the sham taVNS group at week 8 (fourth week of real taVNS following 4 weeks of sham); and 3) the real taVNS group at week 8 vs the sham taVNS group at week 12 (eighth week of real taVNS following sham). Results After four weeks of treatment, MDD patients in the taVNS group showed greater improvement than that of the sham taVNS group as indicated by both Hamilton score changes as well as response and remission rates at week four. In addition, we also found that the clinical improvements continued until week 12 during taVNS. Limitations Patients were not randomized in this study. Conclusions Our results suggest that taVNS is a promising, safe, and cost-effective therapeutic method for mild and moderate MDD.

Acupuncture treatment modulates the corticostriatal reward circuitry in major depressive disorder

“…Lim and colleagues (Lim, Kim, Lee, & Namgung, 2016) found that acupuncture may achieve treatment effects through vagal nerve modulation of inflammatory responses in internal organs. A recent study also showed that direct stimulation of the peripheral branch of the vagus nerve can relieve symptoms in MDD patients (Rong et al, 2016). Taken together, these studies suggest that the vagus nerve may play an important role in acupuncture treatment of depression.…”

Transcutaneous Vagus Nerve Stimulation: A Promising Method for Treatment of Autism Spectrum Disorders

“…A recent tVNS study in migraine patients showed that although both 1 and 25 Hz tVNS can improve clinical outcome in patients with chronic migraine, 1 Hz tVNS can produce greater improvement than 25 Hz tVNS (Straube et al, 2015). Studies have suggested that a frequency between 1 and 30 Hz, pulse width of 130–1000 μs and intensity of 4–6 mA is sufficient to elicit a therapeutic effect (Fang et al, 2016; Rong et al, 2016). Therefore, the suggested parameters for tVNS treatment of ASD may set a frequency between 1 and 30 Hz, or altered frequency between 1 and 30 Hz.…”

“…Previous studies suggested that stimulation intensity could be set to a level that could arouse a tingling but tolerable sensation (Rong et al, 2016). More research is needed to explore the optimal tVNS parameters for different subgroups of ASD.…”

“…The reported mild/moderate side effects include local problems at stimulation sites, such as pain, paresthesia, or pruritus during or after stimulation; erythema, ulcers or scabs, (Straube et al, 2015) and tinnitus (Rong et al, 2016). One potential concern for tVNS is its long-term cardiac safety.…”

“…(3) Disturbed immune function is frequently observed in ASD individuals, the hypothesis of altered immune response in ASD has been proposed (Gesundheit et al, 2013). Studies suggest that stimulation of the vagus nerve could downregulates inflammatory cytokine release (Lerman et al, 2016) (4) tVNS could treat the comorbidities of ASD, such as epilepsy(Park, 2003) and depression (Fang et al, 2016; Rong et al, 2016). In addition, studies suggest that the pathogenesis of ASD, epilepsy and depression may overlap, (Tuchman and Rapin, 2002) and tVNS might have a treatment effect on a common pathway of these three disorders (Lulic et al, 2009; Fang et al, 2016).…”