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
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
- 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.
How well does TMS work? Thase says he's seen meaningful benefit in patients
he's treated -- a benefit also seen in clinical trials.
"The track record for TMS in depression is not 100% successful, but
studies document a pattern of evidence that this has a significant treatment
benefit," he says.
When, if ever, should a patient give TMS a try?
The FDA clearance is for the same patients who did best in clinical studies:
people who did not benefit from one antidepressant medication, but who had not yet
tried a second antidepressant.
"It fits in between first- and second-choice therapies and ECT,"
Thase says. "You would not use it in a patient for whom the depression was
so disabling that hospitalization was required. And you certainly would not use
it for someone who had tried antidepressant treatment of appropriate dosage and
Patients undergoing TMS must be treated four or five times a week for four
weeks. Thase says that during this time, his team starts patients on a new
antidepressant and weans them from TMS treatment.