VNS (vagus nerve stimulation) was initially developed and approved for treatment-refractory epilepsy. Cyberonics conducted one sham-controlled study for treatment-resistant depression, and while this double-blind study showed no statistical benefit over placebo, an open-label extension showed enough benefit to impress someone at the FDA. In a controversial decision in which the unanimous rejection of an advisory panel was overturned, the FDA approved VNS for treatment-resistant depression on July 15, 2005.

Since we last covered this issue (TCPR, Jan 2006), neither VNS nor Cyberonics have fared well. A year and a half after the FDA approval, the Cyberonics CEO Robert Cummins resigned amid allegations that he was inappropriately awarded stock options hours after the FDA decision, shortly before Wall Street opened and the value of his stocks soared. A few months after his resignation, there was more bad news: in May 2007, Medicare announced that they would not reimburse for VNS when used for depression, because their review of the data had concluded that it was not effective. The company’s sales have been down 20% since last year, and they are pulling back on their marketing efforts to concentrate on their core epilepsy business.

Medicare has posted its “decision memo” at http://www.cms.hhs.gov/mcd/viewdecisionmemo.asp?id=195. While very long, it makes for an interesting browse, since it reviews all the extant evidence relating to VNS for depression, and includes point-by-point rebuttals of a variety of pro-VNS arguments. Whether you agree with the decision or not, there’s no question that Medicare spent a great deal of time and brainpower poring over this issue.