From the Guidelines
Vagus nerve stimulators have shown promise in reducing stress and anxiety, particularly in treatment-resistant cases, as evidenced by their approval for treatment-resistant depression and benefits in anxiety disorders 1. The primary mechanism of vagus nerve stimulators involves stimulating the vagus nerve, which is the primary component of the parasympathetic nervous system, counteracting the "fight-or-flight" stress response.
- By stimulating this nerve, these devices can help activate the body's relaxation response,
- lower heart rate,
- reduce blood pressure, and
- decrease stress hormone levels. While these devices show promise, they work best as part of a comprehensive approach to anxiety management that includes other treatments like therapy, medication when needed, and lifestyle modifications. Non-invasive options include transcutaneous VNS devices that stimulate the vagus nerve through the ear or neck, with devices like Nervana, Xen by Neuvana, and Apollo Neuro available for consumer use. These typically require daily sessions of 15-30 minutes, with effects sometimes felt immediately but optimal benefits usually developing over weeks of consistent use. However, it's essential to consider the invasiveness of these interventions and the fact that people selected for these treatments have tried an unusually large number of ineffective treatments, making them different from other people living with treatment-resistant depression 1. Additionally, the FDA has approved implantable VNS for treatment-resistant depression, and research indicates benefits for anxiety disorders as well, but the evidence is not as strong for social anxiety disorder, where SSRIs and SNRIs are considered safe and effective therapeutic drugs 1. In children and adolescents with anxiety disorders, SNRIs such as venlafaxine and duloxetine have been shown to be effective, but the choice of medication should be governed by considerations such as pharmacokinetics, pharmacodynamics, tolerability, cost, and insurance formularies 1.
From the Research
Vagus Nerve Stimulation for Stress and Anxiety
- Vagus nerve stimulation (VNS) has been studied as a potential treatment for anxiety disorders, including obsessive-compulsive disorder (OCD), panic disorder (PD), and posttraumatic stress disorder (PTSD) 2.
- A pilot study found that VNS was relatively well tolerated and showed evidence of acute and long-term improvement in some patients with treatment-resistant anxiety disorders 2.
- The study found that three patients were acute responders based on the Hamilton Anxiety Scale (HAM-A), and there was some improvement in anxiety ratings over time, with statistically significant improvements at 14 of 18 quarters during long-term follow-up 2.
- Another study found that VNS was effective in reducing severity of depression in patients with treatment-resistant major depression, with response rates of 28.6% at 1 year and 60% at 5 years 3, 4.
- While the exact mechanism of action of VNS in anxiety disorders is not fully understood, it is thought to involve the stimulation of afferent vagal brainstem pathways associated with mood regulation 5.
- VNS has been found to be safe and well tolerated, with common side effects including hoarseness, dyspnea, nausea, pain, and anxiety 2, 3.
- Further studies are needed to fully understand the efficacy and safety of VNS for anxiety disorders, but the available evidence suggests that it may be a viable treatment option for patients with treatment-resistant anxiety disorders 2, 6, 5.