Depression pill sales in this country have exceeded the $1 billion mark for years now, even as popular drugs like Zoloft and Prozac turn generic. Sales numbers of these drugs, and similar others, boggle the mind — no pun intended.

And the numbers keep growing. Newer, supposedly better, drugs for depression have more recently hit the market with remarkable success. Drugs like Cymbalta, the gem of Indianapolis-based drug manufacturer Eli Lilly & Co., have caught the attention of patients and prescribers alike. In 2011, Cymbalta sales exceeded $3 billion, representing 14 percent of Lilly’s revenue, according to Bloomberg.com. The popular drug is scheduled to lose its U.S. patent protection in 2013, opening the door for generic production that will, as expected, lower sales.

So it would follow that a FDA-approved depression treatment — anecdotally nearly guaranteed to work, according to some local health care providers — would strike a familiar financial chord with health care–centric Nashville and the myriad of doctors, investors and health care-related business owners who ply their trade here. But that’s not happening.

Enter transcranial magnetic stimulation (TMS), a minimally invasive brain stimulation therapy delivered through a futuristic dental chair-shaped machine that appears to have a mini-magnetic resonance imaging attached. To put it succinctly and without hyperbole, the widespread use of this machine could minimize to the point of extinction the billion-dollar-plus depression pill manufacturing market. But that’s not happening, with only a few machines found locally.

Two years ago, Dr. Scott West, a Green Hills–based psychiatrist, became the first local doctor to acquire the TMS machine. West couldn’t be reached comment prior to the publication of this story and there hasn’t been much hoopla over his purchase. According to local sources familiar with West and his practice, the good doc never intended to spur other local psychiatrists to purchase the chair. Other than a couple of media reports, the availability of TMS treatment in West’s office has largely gone unnoticed.

West was the area’s only physician to have the TMS machine until last summer when Dr. Michelle Cochran, a Hillsboro Village-based psychiatrist, purchased one — and to positive financial results — for her NeuroScience & TMS Treatment Center (formerly known as the Psychiatry Clinic of Hillsboro Village).

According to Chuck Cochran, spouse of Michelle and the TMS program director in Cochran’s office, the $75,000 initial investment — including another $25,000 in add-ons, like service and parts agreements and the like — has been covered and even exceeded over the past year. Dr. Cochran, the center’s medical director and the company, operating under a limited liability concern dubbed AMP Holdings Corp., expects even better results as two more TMS machine purchases are in the offing as are locations for their placement.

“We’re starting to pick out spots,” Chuck Cochran said.

Cochran declined to provide details on the pending real estate deals but said two locations, both in southern Davidson County, are under consideration.

Not surprisingly, insurance companies balk at paying for treatments like TMS. Starting at $8,000 for the minimum number of treatments and approaching $14,000 on the top end — depending on the number of treatments — the patient pool for those who can afford the cost is obviously small. The good news is that a few insurance providers have begun to apply TMS treatment costs to patient deductibles, portending positive things for Cochran and other psychiatrists.

“We’ve found that some insurance providers in the Northeast are approving TMS for payment but not many around here at this point [are],” Chuck Cochran said.

Local health care experts have long held that Vanderbilt University Medical Center often leads the way in advancing treatments like TMS. The point is if VUMC likes the idea — whatever it is — and pursues it to the point of purchase, then it must be significant and worthwhile — so others follow. But, for whatever reason, that hasn’t happened with TMS.

VUMC purchased its TMS machine earlier this year. Craig Boerner, VUMC senior information officer, did not provide financial details but said, to date, no patients have been treated.

Further efforts to connect with VUMC neurology department officials weren’t successful.

So, what might have been a sort of “arms race” to see how many local facilities would offer this cutting-edge depression treatment technology hasn’t materialized. However, if TMS does catch on and results are as positive as they have been for Cochran over the past year, drug manufacturers might need to consider retooling.

For now, it’s Dr. Michelle Cochran leading the way in Nashville.

“TMS has the potential,” she said, “to revolutionize depression therapy and treatment in this country.”