Device for Depression Criticized
FDA Advisory Panel Sees Marginal Effect of TMS in Depression Treatment
Jan. 29, 2007 -- An FDA advisory panel on Friday questioned the value of a
new brain stimulation device for depression, potentially damaging its chances
for FDA approval.
Members of the panel expressed doubts that the machine, called NeuroStar,
helps depressed patients or provides any advantage over placebo treatment.
The device looks much like a dentist’s chair with metal prongs attached to a
It works on the same principle as electroconvulsive therapy (ECT) --
commonly called "electric shock treatment" -- a treatment usually
reserved for severely depressed patients who do not respond to antidepressant
drugs or therapy.
But instead of using electric shocks, NeuroStar stimulates the brain by
sending a focused magnetic field into the brain from outside the skull -- a
treatment called transcranial magnetic stimulation, or TMS.
In 2005, the FDA approved an implantable nerve stimulation device made by
Cyberonics to treat depression.
The implantable device uses vagus nerve stimulation, or VNS, to stimulate
the vagus nerve (which runs from the neck to the brain and relays messages to
the brain) rather than the brain directly. VNS is already used to treat
Neuronetics, the company that manufactures NeuroStar, presented TMS as an
advantage to implantable devices because it does not require invasive
The company sought to show that the device is equivalent to ECT but with
fewer side effects and is more accessible to patients.
“Many patients cannot avail themselves of (ECT) ... cannot afford this
treatment,” says Philip G. Janicak, MD, a researcher who conducted clinical
trials of TMS for the company.
Also, “Only 8% of psychiatrists provide electroconvulsive treatment,” says
Janicak, a professor of psychiatry at Rush Presbyterian Medical Center in
But the advisory panel was generally unimpressed with the company’s studies,
even though they showed a slight statistical advantage in treating depression
symptoms vs. dummy therapy after six weeks of treatment.
Several panelists expressed dismay that patients showed no improvement on
some depression scales and only minor improvement on the ones that did show a
“Perhaps a reasonable person could question whether there has been an effect
at all,” says Thomas G. Brott, a neurologist from Mayo Medical School in
Jacksonville, Fla., and the advisory panel's chairman.
The panel did not formally recommend to the FDA whether or not the machine
should be approved.
But FDA scientists suggested at a public hearing that they were also uneasy
with the company’s results.
Ann Costello, PhD, an FDA medical official, questioned whether the mixed
evidence of effectiveness in Neuronetics’ studies contained “any clinical
Patients who used TMS appeared to avoid the memory loss often seen in those
who undergo ECT.
But Diana Zuckerman, PhD, president of the National Research Center for
Women and Families, told the panel the company’s studies did not show the
device could help patients.
“It’s not a statistically significant difference, and it’s not a meaningful
difference," says Zuckerman, a clinical psychologist and
epidemiologist. "Yes, it is safer than ECT, but it doesn’t appear to
Steve Newman, executive director of the National Alliance for the Mentally
Ill’s Washington, D.C., chapter, was one of a few patients from Neuronetics’
studies who told experts his deep depression eased after being treated with the
“It was like a light switched on,” he says.