FDA OKs TMS Depression Device
Brain-Stimulating Device Cleared for Depression Treatment After 1 Drug Failure
Oct. 8, 2008 - The FDA has cleared the NeuroStar TMS brain-stimulating device for treating depressed adults for whom one antidepressant has failed to work.
It's the first transcranial magnetic stimulation (TMS) device to pass FDA muster. An FDA spokesperson tells WebMD that because the NeuroStar device is not implanted and carries only "moderate" risk, the FDA needed to only "clear" the device and not formally "approve" it.
The clearance comes nearly two years after a January 2007 FDA advisory panel said clinical trials failed to establish that the device was clinically effective. Although TMS-treated patients were twice as likely as sham-treated patients to show clinical benefit, some panel members said this effect was "small," "borderline," "marginal," and "of questionable clinical significance."
Because of these questions about effectiveness, the panel said the device's risk/benefit profile was not comparable to the risk/benefit profile of electroconvulsive therapy (ECT), a highly effective treatment with potentially serious side effects. Although the FDA originally intended to clear the NeuroStar device based on equivalence to ECT, the panel rejected this comparison. The FDA then decided to clear NeuroStar on its own merits.
And TMS truly is different from ECT, says psychiatry professor Michael Thase, MD, chief of the mood and anxiety disorders program at the University of Pennsylvania. Thase has served as a consultant to NeuroStar maker Neuronetics Inc. On the company's behalf, he presented NeuroStar clinical trial data to the 2007 FDA advisory committee.
"TMS is in no way equivalent to ECT in terms of efficacy nor in terms of safety. TMS is less effective but substantially safer than ECT," Thase tells WebMD.
There are important differences between the two treatments:
- ECT, also known as electroshock therapy, uses an electric shock to induce seizure. TMS uses a magnetic field to induce a much smaller electric current in a specific part of the brain without causing seizure or loss of consciousness.
- ECT is extremely effective in treating severe depression. TMS is not so powerful. It is used to treat milder depression, and it works best in patients who have failed to benefit from one, but not two or more, antidepressant treatments.
- TMS is much safer than ECT. Unlike ECT, TMS does not require sedation and is administered on an outpatient basis.