For decades, Nick Fournie battled severe, treatment-resistant depression, CNN reports.
Despite trying more than 10 medications over 10 years, none brought him relief. Side effects from the drugs were so severe that he experienced what he described as “psychotic episodes,” sometimes leaving him unable to function or even leave his house. His wife, Mary, recalls that their life together was deeply affected.
Their breakthrough came when Nick’s sister, a nurse, suggested he explore an alternative approach called vagus nerve stimulation (VNS) — a therapy that uses electrical impulses to stimulate the vagus nerve, a major nerve that links the brain to key organs. In 2005, the US Food and Drug Administration (FDA) approved VNS as an option for adults with chronic or recurrent depression that has not responded to at least four other treatments. For Nick, the procedure turned out to be life-changing.
“It completely changed my life,” said Nick, now 62. “I find joy every single day.”
His story echoes the findings of a newly published clinical trial of VNS for treatment-resistant depression. The large, yearlong study, which involved 493 adults, revealed that VNS can lead to significant improvements in depressive symptoms, daily functioning, and quality of life. While not all participants experienced relief, many found hope where none had existed before.
The vagus nerve acts as a “superhighway” between the brain and the body, said Dr. Bashar Badran, a neuroscientist and associate professor of psychiatry at the Medical University of South Carolina. This major nerve affects the heart, lungs, spleen, kidneys, and intestines. It also plays a vital role in mood regulation, as it helps control the brain’s response to stress and mood-related neurotransmitters.
Vagus nerve stimulation works by implanting a small device under the skin, similar to a pacemaker, which sends regular electrical pulses to the nerve. The pulses stimulate areas of the brain involved in mood control, providing a pathway for potential relief from treatment-resistant depression.
“It’s a very small pulse generator that’s similar to a cardiac pacemaker,” said Dr. Charles Conway, lead investigator of the new study and director of the Center for the Advancement of Research in Resistant Mood and Affective Disorders at Washington University in St. Louis.
The device is implanted beneath the collarbone, with a lead wire that is tunneled to the neck, where it attaches to the vagus nerve. The device sends pulses for 30 seconds every five minutes.
The newly published trial was a large, rigorous effort to determine the effectiveness of VNS in people with severe depression. Conducted at 84 sites in the U.S. from 2019 to 2024, the study followed nearly 500 adults with an average age of 53. On average, these participants had been living with depression for 29 years and had already failed to respond to 13 different treatments.
At the start of the trial, all participants had a VNS device implanted. But only half had the device activated, while the other half served as a control group, with their devices left off. Both groups continued their existing treatments, which could include medications, therapy, or both.
Over the course of 10 months, participants underwent monthly assessments to track changes in their depressive symptoms, ability to complete daily tasks, and overall quality of life.
The results were promising:
- Symptom improvement: 18% of participants with active VNS experienced at least a 50% reduction in symptoms, which is considered a “full response” to treatment.
- Quality of life: 53% of participants in the active VNS group reported meaningful improvements in their quality of life.
Dr. Conway noted that the patients studied were among the most severely affected treatment-resistant depression patients ever examined in a clinical trial.
“What’s really important here is that the patients themselves were reporting that their lives were improving,” Conway said.
While the study offered hope, it was not without its limitations. One key setback was that it failed to meet its “primary endpoint” — a significant difference between the two groups’ scores on the Montgomery-Asberg Depression Rating Scale (MADRS), a tool used to measure depression severity.
The trial did succeed, however, in meeting its “secondary endpoints,” including improvements in depressive symptoms, daily functioning, and quality of life. Experts noted that it is not unusual for clinical trials to miss primary goals while still demonstrating clear benefits.
One possible explanation for the mixed results is the severity of the participants’ depression.
“The degree of resistance in this trial exceeds any previous large, prospective antidepressant therapeutic trial,” the researchers said.
Additionally, some in the “inactive” control group reported mild antidepressant effects. This could be due to the placebo effect or the participants’ awareness that their devices would eventually be activated at the trial’s end.
The exact mechanism by which vagus nerve stimulation affects depression is still under investigation, but scientists have several theories.
- Mood and Emotion Regulation: The vagus nerve connects to areas of the brain that control mood and self-reflection. By stimulating the nerve, VNS may “recalibrate” these brain networks, especially the default mode network, which is known to play a role in depression.
- Neurochemical Release: VNS appears to increase the release of serotonin and norepinephrine — two brain chemicals linked to mood regulation.
- Inflammation Reduction: Chronic inflammation has been linked to depression, and the vagus nerve plays a key role in controlling inflammation in the body. By stimulating the nerve, VNS may reduce inflammation and improve mood.
- Promoting Brain Plasticity: Research suggests that VNS could encourage the formation of new brain connections, helping the brain become more adaptable and resilient in the face of mental health challenges.
Despite FDA approval, vagus nerve stimulation remains financially out of reach for many patients. The cost of a VNS procedure is about $25,000, and insurance coverage is often limited.
In 2007, the Centers for Medicare & Medicaid Services (CMS) declined to cover VNS for depression, citing insufficient evidence. While private insurers often follow CMS decisions, the landscape has shifted in recent years. In 2019, CMS decided to provide “coverage with evidence development,” meaning that people participating in FDA-approved trials could have access to VNS under certain conditions.
This change has improved access, but not for everyone. Conway hopes the new trial results will persuade CMS and private insurers to expand coverage.
“If it was just only medication, I don’t know that he would be alive today,” said Mary Fournie.
With an estimated 30% of the 21 million U.S. adults with major depressive disorder classified as treatment-resistant, the potential for VNS is significant. The fact that nearly 20% of participants experienced a “full response” offers hope for those who have found no relief elsewhere.
Nick Fournie remains on VNS treatment to this day, alternating between two different antidepressant medications as advised by his doctor. He describes his mental well-being as worlds apart from where he was before VNS.
“If it was just only medication, I don’t know that he would be alive today,” said Mary. “This was a miracle for us. It isn’t a magic bullet. It’s work. But it has saved our lives together, and his life.”
