People with depression who are treated with nerve stimulation experience significant improvements in the quality of life, even when their depressive symptoms do not completely disappear, according to results from a national study led by researchers from the University of Medicine of Washington in St. Louis .
The study included nearly 600 patients with depression who could not be relieved by four or more antidepressants, alone or in combination. The researchers evaluated vagus nerve stimulators, which send regular pulses of electrical energy to the brain via the vagus nerve. The nerve originates in the brain, passes through the neck and travels to the chest and abdomen.
The FDA approved vagus nerve stimulation for therapy-resistant depression in 2005, but more recently, it is known that only evaluating a patient's antidepressive response to stimulation does not adequately assess the quality of life, which was the goal of this study.
The findings will be published online on August 21 in The Journal of Clinical Psychiatry.
"When evaluating patients with treatment-resistant depression, we need to focus more on their overall well-being," said lead researcher Charles R. Conway, MD, professor of psychiatry at Washington University. "Many patients have no less than three, four or five antidepressants, and they are barely recovering, but if you add a vagus nerve stimulator, it can really make a big difference in people's daily lives."
No less than two thirds of the 14 million Americans with clinical depression are not helped by the first antidepressant they are prescribed and up to a third does not respond to subsequent attempts with other such drugs.
The researchers compared patients who received vagus nerve stimulation with others who usually received the study, including antidepressants, psychotherapy, transcranial magnetic stimulation, electroconvulsive therapy or a combination.
The researchers followed 328 patients implanted with vagus nerve stimulators, many of whom also took medication. They were compared with 271 similarly resistant depressive patients who received only the usual treatment.
In 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 stimulator did better," said Conway. "To be considered as a person who has responded to depression therapy, he or she should experience a 50 percent decrease in his or her standard depression score, but we observed anecdotally that some stimulant patients reported that they felt much better. although their scores dropped only 34 to 40 percent. "
A vagus nerve stimulator is surgically implanted under the skin in the neck or chest. Stimulation of the vagus nerve was originally tested in epileptic patients who did not respond to other treatments. The FDA approved the device for epilepsy in 1997, but during the testing of the therapy, researchers noticed that some epilepsy patients who also had depression experienced fairly rapid improvements in their depressive symptoms.
In the new study, patients with stimulators had significant gains in quality-of-life measures such as state of mind, ability to work, social relationships, family relationships and leisure activities compared with those who received only the usual treatment.
Research participant Charles Donovan said that he never felt much better when taking antidepressants. He was admitted to the hospital several times before he had implanted a stimulator.
"Slowly but surely, my mood brightened up," he remembered. "I went from basically catatonic to little or no depression, I now have my stimulator for 17 years and I still get sad when bad things happen – such as deaths, recessions, job loss – so it does not make you bulletproof from the normal ups and downs of life, but for me vagus nerve stimulation has been a game changer.
"I never wanted to leave my house before the stimulator," he said. "It was stressful to go to the supermarket, I could not concentrate to watch a movie with friends, but after I got the stimulator, my concentration gradually returned, I could do things like reading a book, the newspaper reading, watching a TV show, and things have improved my quality of life. & # 39;
Conway believes that a better ability to concentrate can be the key to the benefits that some patients get through stimulation.
"It improves alertness and that can reduce anxiety," he said. "And when a person feels more alert and energetic and has a better ability to perform a daily routine, the anxiety and depression levels decrease."