Tiffany Marable was taking nine medications a day, and the depression still would not lift.

She could not get out of bed or stop crying. Holding a job was impossible. Just doing the dishes seemed overwhelming.

“I felt doomed,” said Marable, 32. After years of taking heavy doses of antidepressants, mood stabilizers and other medications at a cost of $3,000 a month, the Aledo, Texas, mother of four agreed to try a new treatment that sounded like something out of a science fiction novel.

Transcranial magnetic stimulation therapy, or TMS, is one of psychiatry’s newest tools in the treatment of severe depression that is unresponsive to medication. It uses short, highly concentrated pulses of magnetic energy to stimulate the part of the brain that is believed to control moods. The magnetic fields are the same type and strength as those produced by magnetic resonance imaging machines, or an MRI.

The magnetic field is applied above the left prefrontal cortex and does not affect the whole brain, said Dr. Gary Malone, medical director and chief of psychiatry at Baylor All Saints Medical Center.

For 37z minutes, patients sit in what looks like a dentist’s chair as 8,000 pulses target an area of the brain about the size of a golf ball, he said.

In October 2008, the Food and Drug Administration cleared the device, made by NeuroStar, for the treatment of severe depression. Almost two years earlier, an FDA advisory panel found that the device was safe but questioned its efficacy. Side effects include headaches and lightheadedness.

It could be an alternative to medication for some of the 15 million Americans who have major depression.

For Marable, who was first treated for depression at age 13, the results were life-changing.

“I could do homework with my kids or go to a game and not be afraid to be around people,” she said. “I just felt normal.”

The treatment, given five days a week for six weeks, is effective in 50 percent to 60 percent of patients and is well-tolerated, said Dr. Deborah Kim of the University of Pennsylvania, where she is researching the use on pregnant women.

About 8 percent of people treated with antidepressants do not respond. Electroconvulsive therapy, also known as shock therapy, is effective for severe depressive episodes but has serious side effects and requires hospitalization.

Even those who improve with medication often find the side effects intolerable. In Marable’s case, the medications triggered a 100-pound weight gain over a year and still didn’t relieve the depression.

In clinical trials for TMS, half the patients experienced an improvement and a third were able to go off medication, Malone said. Of the three patients he has treated with TMS, all responded within two weeks.

It has also been shown to relieve the pain and depression of fibromyalgia, a condition characterized by widespread pain. How long treatment works is unclear because long-term research isn’t available, Kim said.

About 50 percent of patients being treated with TMS at the University of Pennsylvania do maintenance treatment, Kim said.

Still, it’s not for everyone. “If you’re depressed because you had a fight

with your wife or you have addictive issues, this will not help,” Malone said.

For those like Marable whose depression makes it difficult to function, relief comes at a price. The six-week treatment costs about $12,000 and is generally not covered by insurance. But those who self-pay have successfully fought to get coverage, and NeuroStar guides patients through the reimbursement process, Malone said.

Whatever the cost, Marable and her husband, Thomas, said it’s worth it. She has started doing volunteer work, plans to get a job and is able to take care of her children. She also quit smoking.