In recent years, the world has made strides to recognize and treat depression as the serious condition it is. Still, despite this increased awareness, depression remains a common condition in the U.S. According to the National Institute of Mental Health, an estimated 21 million American adults have had at least one major depressive episode – approximately 8% of all U.S. adults. 

Luckily, health care providers continue to research depression, resulting in new treatments. Although not new, one lesser-known treatment could be a key to helping those with depression who haven’t responded to other standard treatments. 

Vagus nerve stimulation

There is a left and a right vagus nerve, which travel from the brain, underneath the skin of the neck, to conduct information between the brain and the heart, lungs and digestive tract. Because this nerve supplies sensory information to the brain, in the ‘90s, researchers began clinical trials for vagal nerve stimulation, or VNS, to treat epilepsy. 

“In this research, they found approximately half of the patients who received a vagus nerve stimulator for the treatment of epilepsy – that didn't previously respond to medications – had a 50% or better improvement in their seizure frequency and severity,” says neurosurgeon Aviva Abosch, MD, PhD. 

Observing that the epilepsy patients treated with vagus nerve stimulation seemed happier, this treatment led to a clinical trial examining the use of the same vagal nerve stimulator for treating refractory depression – or depression that doesn't respond to standard therapies, including psychotherapy and antidepressant medications. 

“Vagus nerve stimulation is a treatment for people with major depression who haven’t responded to the cognitive behavioral therapy and the usual classes of antidepressant medications, such as selective serotonin reuptake inhibitors,” says Dr. Abosch. 

In 2005, the FDA approved vagal nerve stimulation for the treatment of both unipolar and bipolar depression. “While it doesn’t work for everyone, some patients experience a profound benefit for their depression,” says Dr. Abosch. 

Receiving vagal nerve stimulation for depression

The first step in receiving VNS for depression is for your treating psychiatrist to verify that you've exhausted the usual treatments, such as cognitive behavioral therapy and typical antidepressant medications. “If those treatments fail to control your depression, you then become eligible for other, more invasive treatments such as VNS,” says Dr. Abosch. 

During your initial surgery, your neurosurgeon will make an incision in the neck and implant an electrode that wraps around the vagus nerve. The electrode’s tail travels underneath the skin and over the collarbone, connecting to an implanted programmable generator, or IPG, placed underneath the skin of the chest through a separate incision. 

“Your psychiatrist can then access this electrode via an external computer wand placed over the IPG, which allows us to check the battery’s residual voltage and program the stimulation (including the amplitude of the voltage and pulse width delivered), adjusting these stimulation parameters depending on your response over time,” says Dr. Abosch. 

In addition to first exhausting standard treatments for depression, you must also be able to undergo general anesthesia for the surgery. So, if you have conditions that prevent you from receiving a general anesthetic or an uncorrectable bleeding disorder, you’re not a candidate. 

Finally, patients who are actively suicidal need to have this condition addressed promptly before they can be considered candidates for VNS. 

Risks of vagal nerve stimulation for depression

Like any treatment, vagal nerve stimulation has potential risks or side effects. “First, it’s a device, which means there’s always a possibility that it could fail,” says Dr. Abosch. For this reason, occasionally, the stimulator will need a component replaced – the two primary components being the battery, or IPG, and the electrode. 

“Second, there's a risk of infection," says Dr. Abosch. "Any implanted device carries the risk of infection over that person's lifetime, although most infections happen in the immediate postoperative phase – within the first 30 days after surgery.”

Still, any infection after VNS surgery could threaten the device. For example, if you get a small cut that eventually leads to an infection and don't seek treatment, this infection could enter your bloodstream and contaminate the device. Your surgeon would then need to remove the device.

“You can't clear a bacterial contamination of a device without removing it, treating it with IV antibiotics, and then reimplanting the device after the infection is over, says Dr. Abosch. 

Misconceptions about vagal nerve stimulation for depression

Despite increased awareness, patients are still reluctant to report to their health care provider that they have depression. "If you have a broken arm, nobody thinks twice about going to an orthopaedic surgeon and having them fix the fracture," says Dr. Abosch. "But when you have depression, we often consider it a moral failing and are reluctant to seek help.”

“Still, your brain is like any other organ system. There can be problems with it, and there are treatments for those problems," says Dr. Abosch. Unfortunately, there's much more stigma associated with your brain not working correctly, which is what depression is all about. 

“I hope that someday we get past this stigma for the benefit of patients," says Dr. Abosch. "When your brain isn't working properly, you need help with it.” 

Another common misconception about VNS is the checkered history of psychosurgery. During the 20th century, neurosurgeons and neurologists performed procedures to treat depression and other psychiatric conditions that they wouldn't do today. 

“But the surgeries we perform today, like VNS or deep brain stimulation, are different because they don't require severing a connection or taking part of the brain out," says Dr. Abosch. "Instead, we're modulating pathways in the brain – part of a category of procedures called neuromodulation, which modulate brain function without destroying brain areas or connections.”

Learn more about vagal nerve stimulation for depression

The Food and Drug Administration approves vagal nerve stimulation for the treatment of depression. Still, it remains an area of active research to learn more about the underlying mechanism. 

"We don't have all of the answers yet, but we're much further than we were 20 or even 10 years ago," says Dr. Abosch. VNS is just one treatment that physicians can use to help you with your depression.