Nerve Stimulator Appears Effective in Treatment-Resistant Depression
"A typical side effect would be a raspy-sounding voice during stimulation, because the [vocal cords are] also affected," says Rush. The electrical current is on for 3 seconds and then off for 5 minutes, and this cycle is constant 24 hours a day, Rush says. "At the same time, the patient is maintained on the baseline medication regimen. This is an unusual approach for psychiatry, but we are considering this as an add-on therapy," he says.
Although he is enthusiastic, Rush emphasizes the preliminary nature of the findings. Asked to comment on the study, Thomas Thompson, MD, director of the ECT program at Wesley Woods Geriatric Hospital in Atlanta and assistant professor of psychiatry at Emory University School of Medicine, echoed that cautious note. Thompson tells WebMD, "This is very preliminary work, and the findings need to be replicated in a larger study. A lot more work still needs to be done."
If the results are proven in larger studies (the FDA has given approval to enroll another 30 patients in the ongoing trial), Rush says that the stimulator may prove a good alternative to ECT. He says that he and his fellow researchers did some testing that indicates the vagus nerve device may actually improve some mental functioning.
One of the main criticisms of ECT is that it sometimes leaves patients with sluggish responses and impaired memory. Rush says, however, that the improvement may be related to the improvement in depression.
That explanation makes sense to Thompson, who says that although ECT is associated with some changes in mental functioning around the time of the treatments, "We actually see improvements when we retest after treatment if there has been an improvement in the depression." He says that the vagus nerve stimulator may work the same way.
Using the treatment for depression is experimental, but Rush estimates that if it becomes an approved therapy the cost will be "about $10,000 to $12,000 for the device and about $4,000 to $5,000 for the surgery." In this study, all surgeries were "done by neurosurgeons who have implanted [the vagus nerve stimulator] for epilepsy," Rush says.
The study was partially funded by Cyberonics of Houston, manufacturer of the stimulator.