Though depression is often dubbed the common cold of mental health, the disorder can be crippling - and nearly a third of those who suffer find little or no relief in the flood of anti-depressants now on the market.

For them, a new but expensive treatment option may offer hope where everything else has failed. Transcranial magnetic stimulation, or TMS, is an outpatient procedure during which magnetic pulses are focused on a part of the brain that becomes sluggish during .

In essence, the pulses speed things up.

"It saved my life," said Kelsey Pop, a psychiatric nurse in Orlando, Fla. At 29, she has suffered from major depression since she was a teenager - including an acute episode last summer that landed her in the hospital for 11 days. "Over the years I saw psychologists and psychiatrists and therapists, I was put on a series of medications and I was hospitalized several times. Nothing else helped."

The U.S. Food and Drug Administration approved TMS therapy for treating drug-resistant depression in 2008, but insurers have been slow to cover the procedure. In 2012, when Medicare began limited coverage, a handful of Central Florida providers - including Florida Hospital and TMS Therapy Clinic of Orlando - lined up to be ready for the expected increase of patients.

Nearly 10 percent of U.S. adults suffer some form of depression in a given year, and it remains the leading cause of disability for Americans age 15 to 44. The problem is more prevalent in women than men, but no demographic group is immune.

Last month, popular WKMG-Channel 6 news anchor Lauren Rowe announced she had suffered depression for "many years" and needed to take a break to focus on treatment.

Though medications and talk therapy help about half of those diagnosed, for more than 30 percent, drugs prove ineffective. And the side effects can be severe, including fatigue; anxiety; weight gain; difficulty sleeping; sexual dysfunction; stomach and intestinal problems; and headaches.

"We've had patients come to us who recognize that they are depressed, but they're very anti-meds," said psychiatrist Luis Allen, medical director at Florida Hospital's Center for Behavioral Health, who considers TMS one of the biggest breakthroughs in treating depression in decades. "For them, they see this as a viable option, and it's one of the safest."

Pop had suffered profoundly at times - dropping out of college at one point and attempting suicide. Some days she couldn't bring herself to get out of bed. Last year, she agreed to undergo (formerly known as electroshock), considered a treatment of last resort. But it not only failed to ease her depression, it also caused .

It was then that she was referred to Dr. Scott Farmer, a psychiatrist and medical director of TMS Therapy Clinic of Orlando. He suggested the newer treatment might be a good option.

When Farmer first heard about TMS at a national conference in 2004, he remembers thinking, "This is the future."

Unlike electroconvulsive therapy, patients don't need to be sedated. They don't need muscle paralytics to keep from injuring themselves. And there is no risk of memory loss.

"We've seen a 62 percent response rate to TMS," Farmer said of the clinic's patients whose depression has eased significantly or - as in Pop's case - completely. "When you consider these are people who have tried everything else, that's fantastic."

Critics say electroconvulsive therapy has a much higher success rate than TMS, particularly for people severely depressed, though they acknowledge the former comes with much greater risk.

TMS, on the other hand, is done in a medical office, where the patient sits in what looks like a dental chair. A machine aims an intermittent electromagnetic field at targeted areas of the prefrontal cortex.

Patients undergo sessions five days a week for four to six weeks at a cost of roughly $7,000 to $12,000 for the entire process.

"The idea that you can come in, get the treatment in 37 { minutes and be on your way really makes it ideal for a lot of people," said Dr. Richard Holbert, director of TMS at the University of Florida Health Psychiatric Hospital. "We have nurses, business people, lawyers and doctors come in on their lunch hour, get the treatment and then go about their day. The only roadblock is financial."

Of the 100 or so patients he has treated with TMS, Holbert said, only a half-dozen have been reimbursed by their insurers. Should that hurdle be overcome, he and other doctors said, TMS is likely to become more commonly used, both for depression and for bipolar disorder, migraine headaches, Parkinson's disease and schizophrenia.

But not everyone is a good candidate. The treatment in extremely rare cases can trigger seizures. It also can't be used in patients with nonremovable metal, such as an aneurysm clip, in or near their heads.

And not everyone will respond. In a study released in 2013, researchers found that 68 percent of TMS patients interviewed a year after their treatment reported improvement, and 45 percent reported complete remission. Some patients undergo periodic maintenance treatments.

Pop, so far, is in remission. She was so impressed by the therapy that she has since gone to work for the clinic that treated her.

"I went into this not even looking to be happy," she said. "I just wanted to stop being so severely depressed. But now, I wake up in the morning, and I have an excitement about life. For the first time, there is hope."