People with severe, treatment-resistant depression who received a nerve-stimulating therapy showed significant improvement in depressive symptoms, quality of life and ability to complete everyday tasks after a year, according to the results of a national, multicenter clinical trial led by Washington University School of Medicine in St. Louis. The findings are published Dec. 18 in a pair of papers in the journal Brain Stimulation.
The study involved nearly 500 participants at 84 sites across the U.S. All of the participants suffered from severe depression that could not be treated effectively with medication or other approaches. This study represents one arm of the RECOVER trial; the other arm addresses bipolar depression and is ongoing. Three quarters of the participants were so ill they were unable to work. Each participant was implanted with a device that stimulates the left vagus nerve — a major conduit between the brain and the internal organs — but only half the devices were turned on. The researchers tracked the participants’ responses using multiple validated assessment tools. While the primary assessment tool revealed no significant differences between the on and off groups, many of the other measures showed significant benefits to using the device.
“These patients are extremely ill, and most have been for a very long time,” said Charles R. Conway, MD, a professor of psychiatry at WashU Medicine and the principal investigator of the RECOVER trial. “On average, each patient had already tried 13 treatments that failed to help them before they enrolled in the trial, and they had spent more than half of their lives sick with depression. But despite that super-high level of sustained illness, we still see statistically significant, measurable improvements in depressive symptoms, quality of life and functional outcomes.”
The improvements observed are potentially life-changing for these patients with severe, refractory depression, Conway said. Severe depression can render people “paralyzed by life,” unable to accomplish the tasks of daily living. The amount of improvement experienced by the participants could be the difference between being unable to get out of bed and being productive and effectively interacting with loved ones, Conway said.