By Kathleen Berger
A national study led by researchers at Washington University School of Medicine in St. Louis indicates that people treated with nerve stimulation experience significant improvements in quality of life, even when their depression symptoms don’t completely dissipate.
Focusing on patients with depression that could not be alleviated by four or more antidepressants, taken either separately or combined, the study involved nearly 600 patients. Of the 600 patients, 328 had the implanted vagus nerve stimulators, many of whom also took medication. The study found that even when their depression symptoms don’t completely subside, they experienced significant improvements in quality of life.
The researchers evaluated stimulators approved for treatment-resistant depression. The stimulators send regular, mild pulses of electrical energy to the brain via the vagus nerve. The nerve originates in the brain, passes through the neck and travels down into the chest and abdomen.
“The pathway of the vagus nerve into the brain targets many of the regions involved in mood,” said principal investigator Charles R. Conway, MD, a Washington University professor of psychiatry. “The studies that we were involved in actually show that after many months of stimulation, you actually see changes in the activity of these regions. You can think of this as a pacemaker for the brain, where it’s consistently delivering stimulus and the brain eventually has to do something with that.”
In this process, Conway said the stimulation brings about a change in the depression. Researchers discovered that evaluating only a patient’s antidepressant response to stimulation does not adequately assess quality of life, which was the purpose of his latest study.
“There was a 34% drop of depressive symptoms. Instead of a 50% response, they only had a 34% response, but when you look at their quality of life, they were describing themselves as having a clinically significant improvement in quality of life,” said Conway.
Conway said the lives of patients with the implanted nerve stimulators were improving despite symptoms of depression not fully reducing, which is considered a novel observation. Assessing quality of life, the researchers evaluated 14 categories, including physical health, family relationships, ability to work and overall well-being.
“On about 10 of the 14 measures, those with vagus nerve stimulators did better,” Conway said.
Conway believes an improved ability to concentrate may be key to the benefits some patients get from stimulation.
“It improves alertness, and that can reduce anxiety,” he said. “And when a person feels more alert and more energetic and has a better capacity to carry out a daily routine, anxiety and depression levels decline.”
In the new study, patients with stimulators had significant gains in quality-of-life measures such as mood, ability to work, social relationships, family relationships and leisure activities, compared with those who received only treatment as usual.
A vagus nerve stimulator is surgically implanted under the skin in the neck or chest. Stimulation of the vagus nerve originally was tested in epilepsy patients who didn’t respond to other treatments. The FDA approved the device for epilepsy in 1997, but while testing the therapy, researchers noticed that some epilepsy patients who also had depression experienced fairly rapid improvements in their depression symptoms.
Study participant Nick Fournie said the stimulator freed him from a gripping state of depression.
In the HEC video, Fournie and his wife, Mary, explain his long battle with severe depression. Fournie discussed the journey leading them to the vagus nerve stimulator and he explained how he can feel the device working. Mary said Nick’s transformation is a miracle.