The Feinstein Institutes—the research institutes of Northwell Health, New York’s largest health care provider—is home to 50 research labs, 3,000 clinical research studies and 5,000 people raising the standard of medical innovation. We make breakthroughs in molecular medicine, genetics, cancer, brain research, mental health, autoimmunity and bioelectronic medicine.
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Can stimulating the vagus nerve improve mental health?
How vagus nerve stimulation can ease inflammation in the body — and why that matters to our mental health
If you walk into a room with five or more adults, chances are that at least one person in the room is living with a mental health condition. It’s a growing crisis — creating a need for new, safe and effective ways to manage anxiety, depression, post-traumatic stress disorder and more. An innovative, minimally invasive treatment called vagus nerve stimulation has shown promise as leading experts at The Feinstein Institutes for Medical Research at Northwell Health strive to build a deeper understanding of the connection between mind and body.
“Depression, anxiety and other psychological illnesses can occur as a result of inflammation in the body,” said Kevin Tracey, MD, president and CEO of the Feinstein Institutes for Medical Research. “From this understanding comes the possibility to develop therapies, such as stimulating the vagus nerve to reduce inflammation and improve mental health.”
More than one-third of adults said they have a diagnosed mental health condition, with 24% saying they were diagnosed with anxiety and 23% with depression, according to the American Psychological Association’s 2023 Stress in America study. Finding the right course of treatment can be daunting, but through cutting-edge trials, researchers at the Feinstein Institutes are demonstrating how vagus nerve stimulation, a form of bioelectronic medicine, is the key to unlocking this new frontier in mental health treatment.
Inflammation and mental health: It’s not all in your head
Mental illnesses don’t exist solely in the brain — they often also manifest in physical symptoms. Inflammation is one way mental health conditions can take a physical toll on the body, and immune responses like inflammation are linked to conditions like depression, post-traumatic stress disorder, schizophrenia, bipolar disorder and obsessive-compulsive disorder. Dr. Tracey and his colleagues have been focusing their research around a revolutionary question: can stimulating the vagus nerve reduce inflammation and treat depression and anxiety, or even other mental health conditions?
“We know that inflammatory molecules cause depression in humans,” Dr. Tracey said. “Now the question is whether or not we can target the vagus nerve to reverse the process.”
What is the vagus nerve?
The vagus nerve is the longest nerve in the body and helps control breathing, heart rate and immune responses like inflammation. Kevin J. Tracey, MD, president and CEO of the Feinstein Institutes for Medical Research, explains how stimulating the vagus nerve can lead to innovative therapies.
Research published in Nature Reviews Immunology suggests inflammation is connected to depression and other mental health conditions because inflammation can get in the way of neurotransmitters, like dopamine and serotonin, which are critical to regulating our mood, energy levels and more.
While small proteins, known as cytokines, can help control inflammation in the body, some cytokines can make inflammation worse, such as interleukins (ILs), tumor necrosis factor α (TNF), and interferons (IFNs), and when released, impact the ability for neurotransmitters to do their job.
“It’s very plausible that some patients with depression have underlying inflammation and that treatment with vagus nerve stimulation to block the inflammation could help benefit them,” said Dr. Tracey.
The role of the vagus nerve in mental health
The vagus nerve consists of two separate nerves. Each nerve is comprised of 100,000 fibers and runs along either side of your body — starting near where your brain stem meets your spinal cord, running across your neck and chest and into your abdomen. By connecting the brain to the body and the nervous system to the immune system, the vagus nerve acts as the information superhighway, sending signals to each of our organs about how they should function.
“When you take a big breath, your lungs fill with air, the fibers on your vagus nerve send signals to your brain. This activates signals that then return to your heart and slows it as you exhale,” said Dr. Tracey. “The list goes on and on and on. There are literally hundreds if not thousands of reflexes embedded in your two vagus nerves on each side of your body.”
This includes the inflammatory reflex, named for its role in suppressing inflammation. While some inflammation can be good for you as an essential part of the body’s healing process, severe or prolonged inflammation can lead to chronic conditions like autoimmune diseases. It can also interfere with normal brain function and enhance your risk for behavioral health issues.
“If inflammation doesn’t stop, if it goes on chronically or if it’s not reversed, it can damage the body,” Dr. Tracey said. “The key to inflammation is having the right amount in the right place at the right time. My colleagues and I discovered that stimulating the vagus nerve stops inflammation, which has interesting and important implications for using vagus nerve stimulation to treat inflammatory conditions.”
Vagus nerve and depression
A clinical trial conducted at the Feinstein Institutes shows vagus nerve stimulation does, in fact, work to reduce symptoms of depression after studying its effects on women with peripartum depression, a highly prevalent condition in women that often goes untreated.
Women in the study who had mild to moderate symptoms of postpartum depression wore a device that stimulates the vagus nerve through the ear, and after six weeks, researchers discovered it significantly reduced postpartum depressive and anxiety symptoms in 74% of women with postpartum depression.
The FDA approved vagus nerve stimulation for adults who’ve experienced difficulty in treating depression nearly 20 years ago, but with more research like this, the hope is to see more widespread use for other mental health conditions.
Vagus nerve and schizophrenia
Schizophrenia has no known cure, yet impacts the way more than 24 million people worldwide think, feel and behave.
With the support of Wellcome, Anil Malhotra, MD, co-director and professor of the Feinstein Institutes’ Institute of Behavioral Science is studying repetitive transcranial magnetic stimulation (rTMS) for use in treating major mental health disorders like schizophrenia spectrum disorders and psychosis.
Throughout the five year, double-blind study, patients will receive rTMS, which involves placing an electromagnetic coil against a patient’s head every day for several weeks. The coil sends repetitive magnetic pulses, stimulating the nerve cells in the brain that influence mood and depression.
Vagus nerve and PTSD
Post-traumatic stress disorder (PTSD) often develops in people when they’ve experienced a terrifying, shocking event: The feelings can then be triggered and experienced again months or years later. Six out of every 100 people will experience PTSD at some point in their lives, and it’s commonly seen in those who witnessed or were exposed to a traumatic situation, such as first responders.
Like many other mental health conditions, talk therapy or medication are often recommended treatments, but a clinical trial at the Feinstein Institutes is testing vagus nerve stimulation using a through-ear device. Led by Feinstein Institutes researchers, Theodoros Zanos, PhD, and Rebecca Schwartz, PhD, the small trial includes first responders following the World Trade Center attack on September 11, 2001.
Parts of the brain commonly associated with our response to fear and stress are also connected to the vagus nerve, which is why leaders in vagus nerve stimulation believe it has the potential to ease symptoms of psychiatric disorders, like PTSD.
Other areas of focus for researchers include traumatic brain injuries and stroke. “In fact, there are already FDA-approved devices for depression, stroke rehabilitation, and even for reducing the symptoms of opioid withdrawal,” said Dr. Tracey.
How to stimulate the vagus nerve
Physicians can stimulate the vagus nerve by implanting small, jelly bean-sized bioelectronic devices. Typically, the device is inserted into the chest and has lead wires that connect to the vagus nerve in the neck. Some device designs include wrapping around the vagus nerve, like a cuff. Other, non-invasive options are also possible, like ultrasound technology or through-ear stimulation known as ranscutaneous auricular vagus nerve electrical stimulation (taVNS).
With the help of these devices or procedures, bioelectronic medicine can be used to activate the small fibers that make up the vagus nerve, leveraging the body’s own healing mechanisms to reduce inflammation and manage inflammatory conditions like depression, schizophrenia, bipolar disorder and other mental illnesses.
It’s research that’s leading to a better understanding of how inflammation, the nervous system and mental health are connected.
The future of mental health treatment
For patients with depression whose only available treatment options are the traditional route of medications, Dr. Tracey hopes that vagus nerve stimulation will open up new possibilities, allowing patients to choose other treatment options that could better suit their needs.
Dr. Tracey points out that even though antidepressants have been on the market for more than 50 years, only 30-50% of patients with major depressive disorder fully recover by using current approaches like medication or psychotherapy.
“Those numbers aren’t good enough, and with more people being diagnosed everyday with these often crippling conditions, we urgently need to find new ways to treat them,” said Dr. Tracey. “The vagus nerve may be a crucial piece of this puzzle, but we need to commit more resources to studying it.”
By studying how vagus nerve stimulation can expand treatment options for depression and other mental health conditions, researchers hope to lead the charge in forging a path forward for bioelectronic medicine and mental health, one that leads to widespread FDA approval of vagus nerve stimulation as a viable therapy and adoption by insurance companies to make it an accessible and cost-effective treatment option for millions of Americans.
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