According to a study, researchers estimated the quality-of-life(QOL) change associated with treatment as usual (TAU, any antidepressant treatment) versus adjunctive vagus nerve stimulation treatment (VNS + TAU) in a population of patients with treatment-resistant depression (TRD) for 5 years.
People with depression who are treated with nerve stimulation experience significant improvements in quality of life, even when their depression symptoms don't completely subside. The study was published in The Journal of Clinical Psychiatry.
The study involved nearly 600 patients with depression that could not be alleviated by four or more antidepressants, taken either separately or in combination. The researchers evaluated vagus nerve stimulators, which send regular, mild pulses of electrical energy to the brain via the vagus nerve.
The FDA approved vagus nerve stimulation for treatment-resistant depression in 2005, but there has been a recognition more recently that evaluating only a patient's antidepressant response to stimulation does not adequately assess the quality of life, which was the purpose of this study.
When evaluating patients with treatment-resistant depression, we need to focus more on their overall well-being. A lot of patients are on as many as three, four or five antidepressant medications, and they are just barely getting by. But when you add a vagus nerve stimulator, it really can make a big difference in people's everyday lives.
As many as two-thirds of the 14 million Americans with clinical depression aren't helped by the first antidepressant drug they are prescribed, and up to one-third don't respond to subsequent attempts with other such drugs.
The researchers compared patients who received vagus nerve stimulation with others who received what the study referred to as treatment as usual, which could include antidepressant drugs, psychotherapy, transcranial magnetic stimulation, electroconvulsive therapy or some combination.
The researchers followed 328 patients implanted with vagus nerve stimulators, many of whom also took medication. They were compared with 271 similarly resistant depressed patients receiving only treatment as usual. In assessing the quality of life, the researchers evaluated 14 categories, including physical health, family relationships, ability to work and overall well-being.
For a person to be considered to have responded to depression therapy, he or she needs to experience a 50% decline in his or her standard depression score. But we noticed, anecdotally, that some patients with stimulators reported they were feeling much better even though their scores were only dropping 34 to 40%.
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.
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.
It improves alertness, and that can reduce anxiety. 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. Compared to TAU, adjunctive VNS significantly improved QOL in TRD, and this QOL advantage was sustained.
Further, TRD patients treated with VNS experienced clinically meaningful QOL improvements even with depression symptom reduction less than the conventional 50% reduction used to ascribe “response.”