Brain stimulator OK'd for depression

The government has approved the first noninvasive brain stimulator to treat depression – a device that beams magnetic pulses through the skull.

The rapid pulses trigger small electrical charges that spark brain cells to fire. Yet it doesn't cause the risks of surgically implanted electrodes or the treatment of last resort, shock therapy.

Called transcranial magnetic stimulation or TMS, this gentler approach isn't for everyone. The Food and Drug Administration approved Neuronetics's NeuroStar therapy specifically for patients who had no relief from their first antidepressant, offering them a different option than trying pill after pill.

“We're opening up a whole new area of medicine,” says Dr. Mark George of the Medical University of South Carolina in Charleston, who helped pioneer use of TMS in depression. “There's a whole field now that's moving forward of noninvasive electrical stimulation of the brain.”

While there's a big need for innovative approaches – at least one in five depression patients are treatment-resistant – the question is just how much benefit TMS offers.

The FDA cleared the prescription-only NeuroStar based on data that found patients did modestly better when treated with TMS than when they unknowingly received a sham treatment that mimicked the magnet. It was a study fraught with statistical questions that concerned the agency's own scientific advisers.

For a clearer answer, the National Institutes of Health has underway an independent study under way that tracks 260 patients.

Quantifying the benefit is key, considering the price tag. TMS is expected to cost $6,000 to $10,000, says Dr. Philip Janicak of Rush University Medical Center in Chicago, who helped lead the NeuroStar study. That's far more expensive than medication yet thousands of dollars cheaper than invasive depression devices.

The theory: Stimulating brain cells in the prefrontal cortex triggers a chain reaction that also stimulates deeper regions involved with mood.

“Nobody thought this would work; it was a crazy idea. I had to do it at 6 in the morning before the real scientists came in,” MUSC's George jokes .

But, “the brain is an electrical organ,” George adds. “Electricity is the currency of the brain. It's how the brain does what it does.”