Can Stimulating the Vagus Nerve Improve Mental Health?
The device may be especially helpful for those with bipolar depression because so few treatments exist for them, said Dr. Scott Aaronson, one of the senior psychiatrists involved in the clinical trial and the chief science officer of the Institute for Advanced Diagnostics and Therapeutics, a center within the Sheppard Pratt psychiatric hospital that aims to help people who have not improved with conventional treatments and medications.
In general, one of the problems with treating depression “is that we’ve got a lot of medications that pretty much do the same thing,” Dr. Aaronson said. And when patients do not respond to those medications, “we don’t have a lot of novel stuff.”
Vagus nerve stimulation isn’t currently accessible for most people, however, because insurers have so far declined to pay for the procedure, with the exception of Medicare recipients participating in the latest clinical trial.
Dr. Tracey’s research, which uses internal vagus nerve stimulation to treat inflammation, may also have applications for psychiatric disorders like PTSD, said Dr. Andrew H. Miller, the director of theBehavioral Immunology Program at Emory University, who studies how the brain and the immune system interact, and how those interactions can contribute to stress and depression.
PTSD is characterized by increased measures of inflammation in the blood, he said, which “can influence circuits in the brain that are related to anxiety.”
In one pilot study at Emory, for example, researchers electronically stimulated the neck skin near the vagus in 16 people, eight of whom received vagus nerve stimulation treatment and eight of whom received a sham treatment. The researchers found that the stimulation treatment reduced inflammatory responses to stress and was associated with a decrease in PTSD symptoms, indicating that such stimulation may be useful for some patients, including those with elevated inflammatory biomarkers.
Meanwhile, Dr. Porges and his colleagues at the University of Florida have patented a method to adjust vagus nerve electrical stimulation based on a patient’s physiology. He is now working with the company Evren Technologies, where he is a shareholder, to develop an external medical device that uses this approach for patients with PTSD.