PONOKA, ALTA. -- It may sound like the reborn dream of a long-ago medical quack, but modern science is returning to the use of magnets to treat mental illnesses ranging from depression to schizophrenia. Since 1995, a treatment called transcranial magnetic stimulation (TMS) has gone from research to routine at hospitals across the United States, Europe and Australia. A few weeks ago, a small room in a corner of Alberta Hospital Ponoka became the fourth place in Canada where powerful, fluctuating magnetic fields are changing the way sick brains work.

"It has huge potential," says Dr. Doug Urness, who is in charge of Alberta's TMS program.

That program is centred on a modest little metal box about the size of a desktop computer. Snaking out from one side of the box is a cable attached to what looks like a heavy, metal ping-pong paddle.

From the paddle emanates a tightly focused magnetic field, powerful enough to be felt at arm's length. As the paddle is held against a subject's skull and pulses the field on and off, it creates an electrical current inside the brain just as a moving magnet creates a current in a coil of wire.

If the magnet is placed on the right spot, the current it creates has been shown to be remarkably effective in alleviating depression.

Anna, a Toronto lawyer diagnosed with depression in 1991, had been through drug cocktails, electroshock and talk therapy before she became one of Canada's first TMS patients in 2001.

"I was ready to try anything," says Anna (not her real name).

"By the third day (of treatment), it felt like the fog was starting to lift."

Angela, 45, now takes a light dose of a single antidepressant drug, and gets a TMS treatment about every third week.

"It's like a tingling," she says. "It's not uncomfortable at all.

"TMS has been able to consistently bring me back up, whereas drugs were hit and miss."

Magnets have been in and around medical practice at least since the days of Franz Mesmer, who claimed to treat patients with magnetic rods in 18th-century Paris.

"The difference between Mesmer and the current treatment is that this is based on hard evidence," said Dr. Gary Hasey of St. Joseph's Health Centre in Hamilton.

Hasey, who first brought TMS to Canada in 1998, says many don't respond at all to the treatment. But for those who do, it can bring about a 50-per-cent improvement on tests doctors use to measure depression.

It's also being used for obsessive-compulsive disorders, bipolar disorders and epilepsy.

Urness is one of the first using TMS as a treatment for schizophrenia.

Scientists aren't exactly sure why TMS works, but Urness says the latest thinking is that the electrical current generated by the magnets makes neurons in the affected part of the brain more "excitable."

Hard-to-excite neurons require a relatively large amount of electricity to make them active, a condition associated with depression. Sending electricity into the brain seems to make those neurons easier to excite.

"If we can enhance the excitability of those neurons back to a normal level, then that new level of normal functioning will provide symptomatic relief of depressive symptoms," Urness says.

It's the same principle as electroshock therapy. But because electroshock must ram the current into the brain through resistive layers of flesh and bone, it has to use large amounts of electricity. It requires general anesthesia and causes convulsions, confusion and temporary memory loss.

TMS generates the current right inside the brain, allowing doctors to use much lower power levels. TMS's worst side-effect is an occasional mild headache.

Urness's therapy room tells the story. On the side where patients receive electroshock, there is a stretcher, a cabinet full of needles and drugs, and equipment for both a nurse and an anesthetist. On the TMS side, there is a stool.

Not only is TMS a gentle treatment, it could also be relatively cheap to use. Although a new machine costs about $100,000, Urness says using it makes far fewer demands on staff and facilities than electroshock.

Angela says her life used to be like "constantly running through water.

"Everything was just overwhelming," she says. "I wouldn't see friends. I wouldn't answer the telephone."

Now, she has her life back.

"I know now that I have a successful treatment," she says. "I'm like a different person. Life becomes so much easier."