Vagus Nerve Stimulation for Depression: What It Is

TL;DR

• Vagus nerve stimulation (VNS) is a small implanted device — about the size of a small pocket watch — placed under the skin of the chest, with a thin wire wrapped around the vagus nerve in the neck. It sends regular mild electrical pulses to the brain.
• It's been FDA-approved for hard-to-treat depression since 2005, but it's used rarely. Most patients have never heard of it.
• It's specifically for people who have failed at least four antidepressants. This is not a first-line treatment.
• Response builds slowly — over months, not weeks. Recent 5-year data show 68% of patients respond and 43% reach remission with long-term VNS, but the early months are slower than ketamine, TMS, or ECT.
• Common side effects include hoarseness or voice changes (27-68% of patients), cough, and neck pain. These tend to stabilize over time.

This is part of a series of patient-facing posts translating what was discussed at the American Psychiatric Association's 2026 Annual Meeting in San Francisco.

What I'm summarizing

At APA 2026, Stephen Ferber, MD — Assistant Director of the Psychiatric Treatment-Resistance Program at Cleveland Clinic — gave a clinical talk on VNS as part of a broader session on interventional psychiatry treatments. I wanted to translate his presentation for patients and families, because VNS is one of the most under-explained options for people with severe, persistent depression.

What is the vagus nerve, and why stimulate it?

The vagus nerve is one of the largest nerves in the body. It runs from the brainstem, down through the neck, and connects to most of your internal organs — heart, lungs, gut, and more. It's the main highway of the parasympathetic nervous system, the part of your nervous system that handles "rest and digest" functions.

For depression, the relevant point is that the vagus nerve carries signals back up to the brain — into regions involved in mood, attention, fear, and memory: the cingulate cortex, the hippocampus, the amygdala, the insula. By stimulating the vagus nerve with regular electrical pulses, the brain regions implicated in depression get nudged in ways that, over time, can shift mood.

This isn't a hypothesis anymore. The mechanism has been studied extensively. The harder question is how much it helps, how fast, and for whom.

A brief history

VNS was originally developed as a treatment for refractory epilepsy — patients whose seizures didn't respond to medications. FDA-approved for that purpose in 1997.

During those initial epilepsy trials, doctors noticed something unexpected: many patients reported their mood improving alongside their seizure control. That observation kicked off the depression research.

FDA-approved for depression in 2005. The specific approval is for adjunctive long-term treatment of chronic or recurrent depression in adults 18+ who have an active major depressive episode and have not responded to four or more adequate antidepressant treatments.

That last requirement is the key. VNS is not a "try this instead of another antidepressant" option. It's positioned at the end of the medication ladder.

What does the procedure look like?

Two steps:

1. Surgery — a small implantable pulse generator (similar in size to a pacemaker) is placed under the skin of the upper chest, usually on the left side. A thin lead wire is tunneled up to the neck and wrapped around the left vagus nerve. The surgery takes about an hour under general anesthesia.

2. Programming — a few weeks after surgery, the device is turned on and programmed by a psychiatrist. The pulse parameters (how strong, how often, how long each pulse lasts) are adjusted over multiple visits. Most patients can't feel the device working, though some report a sensation when it cycles.

The device runs on a battery that lasts about 8-10 years, after which the generator is replaced in a smaller outpatient procedure.

How well does it work?

Here's where the conversation gets nuanced.

Short-term (10-week) randomized trials show modest effects. The original sham-controlled studies (Rush et al., 2005) showed a 27% response rate at 10 weeks — not dramatically different from no stimulation at all. This made the field cautious about VNS for years.

Longer-term observational studies tell a different story. A 5-year study of 795 patients with treatment-resistant depression (Aaronson et al., 2017, American Journal of Psychiatry) compared people who got VNS with people who continued usual care:

Outcome at 5 years	VNS	Usual care
Response rate	68%	Lower
Remission rate	43%	Lower

For a population that has by definition failed multiple prior treatments, those numbers are meaningful.

The most recent randomized trial (Conway et al., 2025, Brain Stimulation — the RECONCILE study) enrolled 493 patients in a double-blind sham-controlled design over 12 months. Response was 19%, remission 10%. Modest but real — in a population averaging more than 5 prior failed treatments.

The picture that emerges:

• VNS works slowly. Most short-term trials underestimate it because the response builds over months to years.
• It's better than what these patients had been doing, which is failing antidepressant trial after antidepressant trial.
• It's not as fast as ketamine or as well-targeted as TMS for treatment-resistant depression — but for some patients, particularly those who haven't responded to either, it offers a different option.

What are the side effects?

VNS is generally well-tolerated, but the stimulation does produce some predictable effects because the vagus nerve also controls voice, swallowing, and the cough reflex. From Ferber's data:

Side effect	How common
Hoarseness or voice change	27–68%
Cough	6–29%
Neck pain	13–21%
Shortness of breath	8–23%
Headache	4–22%
Difficulty swallowing	4–21%
Tingling sensation (paresthesia)	4–16%

Most of these stabilize after the first few months. The voice change is the most common and persistent — for some patients it becomes noticeable only when the device is cycling; for others it's continuous.

Who is VNS for?

The honest answer, based on Ferber's clinical experience: VNS is for the patient who has been through everything else.

Specifically:

• Failed 4 or more adequate antidepressant trials. Not just tried — adequate trials, meaning the right dose for long enough.
• Cannot access or has failed other interventional treatments (TMS, Spravato, IV ketamine)
• Doing maintenance ECT but the intervals between treatments are too short to live a functional life
• Has responded to ECT or other interventional treatment but the effect isn't durable — VNS provides continuous low-level stimulation that may help sustain remission

Most patients I see have not tried VNS — and most patients I see also have not tried at-home ketamine therapy, which is typically a much more accessible next step. VNS is a real option in the toolkit, but it's near the end of the toolkit for a reason.

What VNS is NOT for

To be direct about the limits:

• Anyone who hasn't first tried multiple antidepressants. This is by definition a treatment for people whose depression has not responded to standard medications.
• People with cardiac conduction abnormalities, right vocal fold paralysis, or sleep apnea — these are relative contraindications. Always discuss with a specialist.
• People with severe personality disorder or active substance use disorder — also relative contraindications, because the maintenance work required is substantial.
• People with bilateral or left vagotomy, or who would need diathermy — these are absolute contraindications.

What does the path look like?

If you're a patient considering whether VNS could be relevant for you:

1. Document your treatment history. What antidepressants, at what dose, for how long, with what response. Without this record, no specialist can evaluate whether VNS is appropriate.
2. Consider whether you've tried the faster options first. Spravato, TMS, and at-home ketamine therapy all reach patients faster and with less procedural overhead.
3. Ask your psychiatrist for a referral to a treatment-resistant depression program — academic centers like Cleveland Clinic, Mayo, and major university hospitals run these. A specialist clinic is essential because programming the device correctly takes experience.
4. Understand the time commitment. Programming takes months. Response builds over more months. This is not a quick win — it's a long-term investment in a chronic illness.

How this fits in the broader picture

The standard treatment ladder for depression, per the conversations at APA 2026:

• Step 1: First antidepressant (SSRI or SNRI)
• Step 2: Switch to a different antidepressant
• Step 3: Combine medications or add Spravato (esketamine)
• Step 4: TMS, ECT, or IV ketamine
• Step 5: VNS or experimental treatments

VNS sits at Step 5 not because it doesn't work, but because the procedures and time investment make it appropriate after faster options have been considered.

If you've tried two antidepressants and they haven't helped, the more useful conversation is about Step 3 and Step 4 — including ketamine therapy at home, which is accessible, doesn't require surgery, and has the strongest evidence base for rapid antidepressant response. VNS becomes the conversation if the faster options haven't been enough.

References

• Aaronson ST et al. American Journal of Psychiatry 2017 — 5-year observational study of VNS for treatment-resistant depression (n=795)
• Conway CR et al. Brain Stimulation 2025 — RECONCILE trial of VNS in treatment-resistant depression (n=493)
• Rush AJ et al. Biological Psychiatry 2005 — Randomized controlled acute phase trial of VNS for TRD
• Kamel LY et al. Journal of Neurological Sciences 2022 — Update on VNS for treatment-resistant depression

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Related Articles

• APA 2026 Annual Meeting Recap: What I Heard
• Spravato vs Ketamine Infusion: Cost & Effectiveness
• Racemic vs S-Ketamine vs R-Ketamine: Key Differences

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