Wasn't electroshock abandoned years ago?
Not entirely, but its use did decline dramatically. Electroshock therapy began in the 1930s, when Italian psychiatrists discovered that administering strong shocks to the brains of mentally ill patients sometimes relieved their symptoms. But by the 1970s, electroshock therapy became widely viewed as barbaric and ineffective, leaving its subjects vacant-minded shells of their former selves. That grossly simplistic view resulted partly from egregious misuse of the technique. At the Georgia State Sanitarium in the 1940s, for example, a patient could be administered a "Georgia power cocktail" just for being uncooperative. The use of electroshock as mind-erasing punishment was dramatized in the 1975 film One Flew Over the Cuckoo's Nest, and that negative portrayal almost served as a death knell for a practice derided as "Edison's medicine." The use of electroshock fell from some 300,000 patients a year in the early 1960s to just 33,000 by 1980. But in recent years the procedure has experienced a resurgence, and is now used to treat about 100,000 patients a year.

Why has it come back?
Some psychiatrists have found that electroconvulsive therapy, as it's now called, is the last, best hope for patients suffering from deep, unyielding depression. "It's a treatment that is lifesaving for those people," said psychiatrist Max Fink, a leading defender of the practice. Today ECT is usually administered in a hospital to patients under anesthesia, in conjunction with powerful muscle-relaxants that suppress convulsions. An electric current pulses through the patient's brain for a few seconds, triggering a seizure that can last for up to a minute. After six to 12 sessions, advocates say, ECT brings about a complete remission of symptoms in 75 to 85 percent of patients, though critics say the relief is only temporary.

How does it work?
That is still something of a medical mystery. A recent study that used MRIs to study the brains of nine patients undergoing electroconvulsive therapy found that the seizures disrupt the normal patterns of blood flow and metabolism in the brain, dampening connections in the left side of the dorsolateral prefrontal cortex — a region of the brain associated with negative thoughts, criticism, and anxiety. The same region in the right hemisphere appears to process uplifting, optimistic, and cheery ideas. Mental health and clear thinking require a balance of both, neuroscientists believe. ECT, the researchers speculate, "might act to rebalance hemispheric activity."

But is it safe?
The medical establishment thinks so. James H. Scully Jr., chief executive of the American Psychiatric Association, calls ECT "extremely effective and safe," and maintains that advances have banished the risk of brain damage. Not everyone is convinced, however. "It's a temporary blunting of your feelings, so you feel better for a while, then you feel worse, and now you've got the memory loss and brain damage," said psychologist John Breeding, an anti-ECT activist. Patients come down on both sides of the question of whether the side effects are worth braving. Electronics technician Bill Russell of Mill Creek, Wash., said he experienced months of debilitating short-term memory loss and confusion after his ECT treatments. But for him, that was a small price to pay for relief from the black depression that had plagued him since high school. "When the fog started to clear, it was like waking up from a bad dream," he said.

What about long-term effects?
That is the subject of fierce debate. Psychiatrist Richard Abrams, founder of a company that makes an ECT device, said that not one of his patients over three decades ever reported prolonged memory loss, the side effect most associated with the procedure. But while ECT machines — and therefore the treatment — have been subject to U.S. Food and Drug Administration regulations since 1976, there have been no large, long-term studies of patients. One federally financed 2007 study of 347 patients found worrisome instances of long-term memory loss and residual problems with thinking and learning. But the APA and many mental-health specialists insist that decades of use have proved that electroshock is safe. Last year they petitioned the FDA to remove ECT machines from their current "high-risk" status, making the treatment available to more patients.

Will that happen?
The FDA faces a difficult choice. After the agency asked for comments from patients and doctors, most physicians favored removing restrictions. But nearly 80 percent of the 3,045 comments from patients and their advocates asked for stricter oversight or even an outright ban on the treatment. Peter Breggin, a psychiatrist in Ithaca, N.Y., said the medical establishment sees electroshock as a way to make money off "elderly depressed women on Medicare." But whether or not the FDA opens the door to more widespread use, said University of Iowa psychology professor Jane Paulsen, electroconvulsive therapy will remain available for the most severe cases of depression. "We're not going to be shutting down ECT," she said.

Saving Princess Leia
Carrie Fisher spiraled into the worst depression of her life after a close friend died in 2005. "I was as close to being suicidal as you can be without being suicidal," said the 55-year-old actress, novelist, and Star Wars legend. "I was devastated." When anti-depressants and psychotherapy failed to help, she turned to ECT. "Over time, this f---ing thing punched the dark lights out of my depression," she said. "It was like a mute button muffling the noise of my shrieking feelings." Now she's come to depend on shock treatments every six weeks to keep her demons at bay, though she says the cure can be "a bitch on memory." ECT's most common side effect, temporary memory loss, does have an upside, she said. She forgets movies she's just seen, but now "I can be entertained by them all over again."