Implanted device delivers relief from depression

Thursday, August 11, 2005

By JULIE DAVIDOW
SEATTLE POST-INTELLIGENCER REPORTER

Lana Sanderson felt like she'd run out of options.

After decades of battling severe depression, nothing -- not anti-depressants, not psychotherapy, not even electroconvulsive therapy -- could break the cycle of debilitating sadnesses and manic highs.
VNS, an implanted medical device.

So, in November 2000 she had an experimental device implanted in her chest at the University of Washington Medical Center.

A pocket-watch-sized battery is attached to a thin wire that runs up to and wraps around the vagus nerve on the left side of her neck. Every five minutes, the device sends an electrical charge up the wire, through the nerve to stimulate Sanderson's brain. The charge lasts for 30 seconds.

Last month, in a controversial move, the U.S. Food and Drug Administration approved the Vagus Nerve Stimulator, or VNS, for patients with treatment-resistant depression. Only patients who've tried at least four other therapies without success should receive the device, according to the FDA.

"These are people with long-standing depression who don't get better," said Dr. David Dunner, head of the UW's Center for Anxiety and Depression, who has conducted studies with VNS. "Either they keep relapsing or they just never improve."
Illustration

An estimated 20 percent of patients with major depression fail to respond to multiple therapies.

The VNS device, including surgery, costs between $20,000 and $25,000, according to Cyberonics Inc., the manufacturer. In the wake of the FDA's approval, insurance companies are now deciding whether to cover VNS for depression.

The vagus nerve connects the brain to many areas of the body, including the heart, lungs, kidneys and larynx. (One of the side effects of the device is hoarseness when it's on.)

Sanderson, 50, said she noticed a small but significant improvement in her ability to concentrate after receiving the device.

"That, I'm pretty sure, was a result of the VNS treatment," said Sanderson, who has been diagnosed with bipolar disorder. She abandoned a successful career in pharmaceutical sales in 2000 because of her illness. "It's hard for me to say how much the VNS has helped versus other components of my treatment, but I feel that VNS is an important component."

No one knows why VNS, which was approved to treat epilepsy eight years ago, seems to help depressed patients.

In fact, some question whether it actually does.

Dr. Richard Malone, professor of psychiatry at Drexel University in Philadelphia and a member of the FDA advisory panel that considered approval for VNS, said he found the evidence presented by the manufacturer unconvincing. The committee voted 5-2 to approve the device.

"FDA approval allows the company to advertise VNS as an effective treatment," Malone said. "I'd be concerned that people in the general public would be making an assumption that in my mind isn't true."

VNS first arose as a possible treatment for depression after researchers noted an improvement in the mood of epilepsy patients who had the device.
Dr. David Dunner
Zoom Scott Eklund / P-I
Dr. David Dunner, director of the UW's Center for Anxiety and Depression, displays the Vagus Nerve Stimulator, which sends an electrical charge to the brain and seems to help patients suffering from treatment-resistant depression.

And Dunner said his research indicates that VNS is effective for some people with stubborn depression.

However, the only randomized, controlled study (the gold standard for medical research) looking at VNS did not prove the device effective. That could be because the eight-week trial didn't last long enough, Dunner said.

A later study compared those who'd been implanted in the first trial with another group of depressed patients. That study found that patients with VNS plus other treatments did better than those without the device.

"I think the idea is you don't expect this to cure you right away," said Dunner, who is being paid by Cyberonics to present data on VNS at medical conferences later this year.

That may be the case, say critics, but without the evidence, VNS shouldn't have been approved.

"I'm at a loss to explain it," said Dr. Peter Lurie, deputy director of the Health Research Group at Public Citizen, a consumer watchdog organization founded by Ralph Nader.

Critics also say the second study isn't valid because the participants weren't chosen at random.

In addition, patients with VNS continued to receive other types of therapy, making it difficult to determine -- for those who improved -- which treatment worked.

VNS is also being studied as a treatment for anxiety disorders, Alzheimer's disease, migraines and bulimia, according to Cyberonics.

"I'm inherently skeptical of drugs or devices that make very diverse claims," Lurie said. "Anything that treats everything may very well treat nothing."

In addition to the potential complications from surgery, other side effects of VNS include reports of shortness of breath and neck pain, Dunner said. There have also been several cases of heart problems associated with the electric stimulation, according to Public Citizen.

But Sanderson said she was willing to try something, no matter how uncertain its benefits.

"When someone has seriously treatment-resistant illness, they have to do something," she said. "Having VNS is certainly a small risk as compared to the 15 percent risk of mortality of untreated bipolar disorder."

This month, Sanderson got engaged -- a commitment she says wouldn't have been possible while she was still mired in depression.

"I'm well and I'm happy and I'm going to have a wonderful marriage."

P-I reporter Julie Davidow can be reached at 206-448-8180 or [email=juliedavidow@seattlepi.com.]juliedavidow@seattlepi.com.[/email]

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