They know that Madeline's depression is being treated with electroconvulsive therapy at St. Joseph's Hospital in Tampa. Once every six weeks, since March. And that it "gave me my life back,'' Madeline says cheerily. "If people think it's barbaric today, well, they're ignorant.''

Electroconvulsive therapy - which practitioners prefer to the term shock therapy - means many things to many people. Proponents say that it is enormously effective in the short run and that it may be far safer than antidepressant drugs. Opponents argue it damages the brain and that the temporary relief of depression is no substitute for some patients' profound and permanent memory loss.

Either way, electroconvulsive therapy has returned to mainstream medicine. In the Tampa Bay area, a handful of hospital-based psychiatrists perform the procedure on their most severely depressed patients, many of them older, most suicidal and psychotic. All are clearly unresponsive to medication. The typical course is a series of six to 12 treatments over a period of a few weeks. Then the therapy is reduced to one treatment a month or less, depending on the patient's relapse rate.

Memory loss and confusion are common side effects of shock therapy, and doctors admit there is no way to predict the severity of a patient's loss. It ranges from slight, forgetting only those events just before and after treatment, to severe, forgetting incidents and information acquired months or years before.

Nonetheless, "it's the best thing that ever happened to me,'' says Madeline, as she lies on a bed minutes before her treatment. James Adams, medical director of psychiatric services at St. Joseph's Hospital, and Malcolm Klein, an anesthesiologist, are at her side. So are several nurses.

They will monitor her blood pressure, her respiratory rate, her heart rate and blood oxygen level throughout the procedure. They will also administer a muscle relaxer and a very short-acting anesthetic; for three to five minutes, a machine will do the breathing for her.

But it is the electrodes on Madeline's temples that are at the center of all this attention. With a nod from James, a box the size of a stereo receiver delivers a pulsing, electrical charge about one-fourth the power of that used to revive a heart by electrical stimulus. The charge surges through her brain, inducing a seizure or convulsion. For 57 seconds. That goes virtually undetected by observers except for the slight strain of a muscle in her neck - and a paper strip from the electroconvulsive therapy machine. It spits out a jagged squiggle, similar to seismograph recordings of an earthquake.

Within five minutes, Madeline is awake and answering questions. And smiling at the people around her.

"I think of it as ECT of the heart and ... nobody thinks anything about starting the heart with an electrical shock after heart surgery,'' says Klein, who has worked with shock therapy patients since 1992.

Adams, who has administered the therapy since 1990, is likewise pragmatic. He considers it a treatment of last resort, only for the severely ill, despite the remarkable success he has seen in his psychiatric practice. Up to 95 percent of his patients felt their depression subside after the therapy.

Yet science continues to wrestle with precisely why it works, and how. And the public continues to perceive the procedure as a harrowing, horrible form of torture, like that depicted in the movie, "One Flew Over the Cuckoo's Nest.''

Electroconvulsive therapy was introduced in 1938 by an Italian scientist who tried it on several patients. It apparently relieved their depression and quickly became something of a psychiatric fad, applied to the mentally ill with little regard for accurate diagnosis or side effects.

By the late 1960s, the therapy had fallen out of favor. Only in the last 10 to 15 years has it become more acceptable, as researchers have modified the electrical charge and minimized the patient's discomfort. Nowadays, for example, patients get a muscle relaxer. For years they didn't, and fractured bones often followed the induced seizure.

The technique may be modified in some patients, since an electrical charge can dramatically alter blood pressure or heart beat. Nevertheless, many practitioners feel it is less risky than drugs, particularly in patients whose conditions are complicated by antidepressants: pregnant women, the elderly, the seriously physically ill.

Harold Sackeim, chief of the department of biological psychiatry at New York State Psychiatric Institute and one of the country's leading electroconvulsive therapy researchers, theorizes that the brain of a depressed person is actually working too hard and too long, like an engine that idles too fast. The therapy slows the idle. As strange as it sounds, Sackeim says, research on individuals who are catatonic - who don't respond to their environment - show that their brains are "literally buzzing away.''

"I have patients who have appeared on Broadway the night of their ECT,'' Sackeim says.

In England and Sweden, electroconvulsive therapy is a first-line treatment. If you are hospitalized for depression, shock therapy is among your first choices, not your last, Sackeim says. In the United States, the therapy is far less common. About 50,000 patients a year receive the therapy and, without insurance coverage, it costs about $500 a treatment.

It also requires the patient's signature on a lengthy legal document. "To my understanding, it is the most detailed consent form in medicine,'' Sackeim says.

In fact, American Psychiatric Association guidelines for electroconvulsive therapy, issued in 1990, fill more than 200 pages. And at St. Joseph's Hospital, no patient can receive it unless they first view a videotape of the procedure and sign a complex consent form. Furthermore, Adams says, a patient who is ruled incompetent cannot receive the therapy unless a motion requesting the procedure is filed in court.

This does not impress Linda Andre, a single mother from New York City who heads the Committee for Truth in Psychiatry. This group of about 500 members, many former recipients of the treatment, asserts that patients who receive shock therapy are poorly informed about the consequences; specifically, they aren't told about the risk for profound memory loss.

The group lobbies legislators, demanding more detailed informed consent laws and railing at political and medical bureaucracies which, Andre says, tend to regard members of the organization as "just plain crazy.''

"Shock therapy is ... Russian roulette,'' says Andre, who in the early 1980s was treated with electroconvulsive therapy during an involuntary hospitalization she can't recall. The result: Andre says she lost memory, intelligence, personality.

"I don't feel like the me I was supposed to be,'' she says sadly. Andre also says her problems have been medically documented, yet the scientific community is clearly unmoved by her complaints. One prominent researcher, Andre says, poked her at a convention and pronounced, "You're alive, aren't you?''

Another outspoken opponent of electroconvulsive therapy, author and psychiatrist Peter Breggin, is even more direct. He says it should be outlawed. Despite attempts at such regulation, the therapy is not illegal anywhere in the United States, and Texas is the only state where it is restricted by law. It cannot be performed on patients 16 or younger.

"My colleagues have done as much brain damage to patients as the public and the legal profession will allow them to do,'' says Breggin, a professor in the counseling department at Johns Hopkins University in Baltimore.

"Of course, if you take the average person and make them retarded, they are going to be grinning. It's because their brains are grossly damaged during this procedure. And sure ... it produces an unrealistic euphoria.

"You can't find 20 patients who've been helped by ECT. That's a farce.''

Sackeim is quick to react to Breggin's comments. He says that the term "brain damage'' applied to the therapy is inaccurate at best and silly at worst, and "completely out of keeping with the scientific understanding of ECT.''

And though he agrees that memory loss is among the side effects associated with shock therapy, Sackeim says that there is often improvement in attention and concentration.

Furthermore, "here at Columbia, we are some of our most severe critics,'' Sackeim says. He is in the midst of a $4 million study funded by the National Institute of Mental Health. His goal is to determine how and why depressed patients experience a relapse, and whether electroconvulsive therapy makes a difference.

Madeline is merely glad that today, and for the next few weeks, it seems to work for her. She hasn't lost any memory. In fact, she thinks her memory is better than before. And after a lifetime spent addicted to diet pills - including 13 years experimenting "with every antidepressant in the world'' - Madeline is convinced that shock therapy is her salvation.

She no longer needs that garbage bag full of pills she once kept in the trunk of her car.

"By the time I got here, even if someone said you were going to lose memory, I didn't care,'' she says. "I had nothing to lose.

"All I know is I don't dread waking up anymore. I'm not depressed. I've lost 22 pounds. I would just like people to know that if they are at the end of their rope, they should give it a try. No, it's not a cure, but it's a good treatment.''