She was schizophrenic. No, epileptic. No, that's not right, she was just hopelessly crazy. Give her a pill. Give her a shot. Strap her down, lock her up, give her a lobotomy.

What was really going on inside Andrea Biaggi's head were Sheba and Anton, Joseph and Dara, Philippe, Little Andrea-Ellen, sexually promiscuous Bridget, lesbians Cathleen and Elizabeth, Sister Jeanine, Mother Mary, The Angry One, The Monster, Super Andrea, Nothing. Especially Nothing.

Creations, perhaps, some 28 altogether. Fragments of her shattered self, perhaps. But the real Andrea was only rarely in control. It was the others -- sometimes more than one at a time -- who governed her often bizarre and incomprehensible behavior. Most of the time she remembered none or very little of what went on, but she heard the voices.

Sheba and Anton killed the cats. Joseph, her mind's incarnation of her dead father, burned her with caustic chemicals or slashed her with knives, then worried the scabs so the wounds festered. Her mother's voice intoned throughout, "You deserve to be punished. You're bad."

Super Andrea held down a high-level, high-pressure job and performed brilliantly. Little Andrea-Ellen cowered in the closet. Bridget enjoyed casual sex, but then one of the others, The Angry One, maybe, or Dara, her mother image, would punish her sinfulness and Philippe would try to make sure it could never happen again -- with pins, with acids, with suicide attempts that often landed her in hospitals.

Andrea herself felt nothing. Because Nothing had taken not only the pain upon himself but the knowledge of those toddler years of unspeakable physical and psychological torture: repeated, unremitting abuse at the hands of her genuinely deranged father and of her mother, whose own escape was to blame her pathetic four-year-old daughter for his hideously aberrant behavior, piously telling her it was "God's will." All through the years, Nothing kept Andrea from feeling -- when Philippe used the Drano crystals, when Dara burned her arms with oven cleaner, and all those other "crazy things." Under no circumstances would Nothing ever let Andrea know.

Until five years ago, when Andrea Biaggi met Dr. Eugene Bliss, it never occurred to her that she might be what they call a "multiple personality." She simply believed, as her family and many of her therapists had assured her throughout the 31 troubled years of her life, that she was "hopelessly, incurably crazy . . . bad and evil and crazy."

And when Bliss suggested that he not only knew what her problem was but thought he could cure her, "Why," she says today, "I thought he was the craziest therapist I'd ever seen."

Andrea Biaggi is not her real name. Although her parents are dead, her big Corsican-American family is scattered around the country, six brothers and sisters victimized by what they knew about Andrea but never told. They do not know of her sessions with Eugene Bliss, nor of the book -- "Prism: Andrea's World" -- that she wrote with him and his son, writer Jonathan Bliss.

Nor do Andrea's employers in Salt Lake City, where she holds down a responsible job. For television appearances she wears a wig and sunglasses.

Today her integrated or "fused" personality is full of the kind of bubbling wit and intelligence that no one would be likely to associate with the anguished, haunted (and haunting) group of shadowy selves that spent her life warring among themselves inside her head.

"I never knew from one minute to the next what was going to happen," she says now. "I had to hide so much."

"Andrea and people like her are unbelievable hypnotic virtuosos," says Eugene Bliss, an avuncular University of Utah psychiatrist who, after some 30 years of relatively traditional practice, has emerged in the last half-decade as a specialist on multiple personality disorder.

"People with multiple personalities have been practicing using spontaneous hypnosis frequently since the ages of 4 or 5, and by the time they are adults they've had a hell of a lot of practice. They can cope with all sorts of nasty things without knowing it."

Andrea's case is fairly typical, despite the seemingly bizarre nature of her symptoms and the events that precipitated them. In fact, according to Dr. Frank W. Putnam, a recognized authority on the disorder and part of the National Institute of Mental Health team at St. Elizabeths Hospital, most multiples have been "victims of extremely sadistic, usually sexually oriented abuse that occurs before the age of 12, usually at about 4, 5 or 6, and continues for a number of years."

Putnam has never seen Andrea, nor was he aware of her book. Nevertheless, characteristics he described as "typical" of multiple personality disorder fit the particulars of her case -- the childhood abuse, the "creation" of numbing or protective personalities that later turn against the host personality, producing self-mutilating behavior.

"You see that over and over," he says. "Typically you find an analgesic personality for the injuries to the body, and a personality that idealizes the abusive parent or parents." The more virulent the abuse and the longer it lasts, the more personalities are likely to be created, he says. And as difficult as therapy with adults can be, children who have dissociated can be successfully treated within weeks.

Putnam also cites new evidence suggesting that a "child witnessing violence may have an even more powerful traumatic experience than a child actually having had the violence directed at the self." A young victim of violence "may be numb or stunned," he says, but seeing violence is "a very potent trauma, and one largely overlooked."

Andrea's recurrent compulsion to kill cats was found to have stemmed directly from an episode of witnessed violence, an incident that she repressed until late in her therapy, when Little Andrea-Ellen, a helplessly terrified 5-year-old self, was "persuaded" to come out.

Her father worked as a maintenance man in a hospital. One day he brought Andrea to work with him. She had found a kitten . . .

From the book:

"It was hard with the kitten to go down. The stairs went to the big room where my father worked . . . He was angry like wild. He scares me. He put a dress on me in the morning and was nice to me. But he was angry . . .

"He grabbed me and the cat. The cat kept running. He kept wanting me to touch him. He kept twisting my hand. 'Just let me get kitty -- please Daddy -- let me go home.' He hit me. I wouldn't do what he wanted. I kept saying I wanted the kitty.

" 'All right, if you want the kitty, I'll give you it. You want this kitty?' He was real angry. He pulled the furnace door open and threw the kitty in the furnace -- then I ran up to him, and I was screaming and crying and I kept begging, 'Please take the kitty out.' He said, 'If you want that kitty, do what I want and I'll get the kitty.'

"I thought he could do it. I really did. That is when I did what he wanted. First he wanted me to do things to him, and then he did things to me. He pulled me into a dark corner. I hated it, but I thought I could save the kitty. It was my fault the kitty died.

"He put my clothes on. 'Now, Daddy, you promised the kitty.' He started to laugh. 'You dumb kid, don't you know the kitty is dead!'

"Then he opened the furnace to show it was dead. He said he would put me in the furnace if I told anyone. I didn't feel anything then. I didn't feel my body. I didn't cry. I wasn't afraid, and I didn't care. I didn't feel or care anymore."

Much of the time nothing seemed to be very wrong with Andrea Biaggi. With a few exceptions -- when periods of hospitalization could not be hidden, for example -- she appeared to lead a more or less normal life. Super Andrea, who was created to keep her from flunking French in high school, kept achieving at a high level, so high that her frequent "dropouts" were more than compensated for.

Even during her therapy, when she was consciously reliving her lifetime of horrors, episode by episode, her coworkers never knew.

"Now that," says Eugene Bliss, "is really one of the crazy parts of the whole thing."

"No one at work," Andrea says, "has ever had an idea. I can describe a time when I was in Boston. I killed a cat. I didn't know what to do, and in one of the more dramatic examples of the split, that evening I did a training workshop for adults. Everybody was happy as a little clam with me. I had totally blocked out what had been going on that day. I got back in my car and -- wham -- just the smell and I was gone, instantly. I could barely make it back home, and I couldn't function for a week."

The anger Andrea felt toward her parents, twisted by her misplaced guilt against herself, is no longer self-directed. But she does harbor a lasting bitterness toward the mental health establishment, which alternately drugged her, exposed her to inappropriate therapies and, she says, brought her "within a hairbreadth" of a lobotomy without so much as a glimmer of what her problem really was.

"It is so scary to think how those mistakes ruin somebody's life. You go to one therapist with a problem and you're told you're schizophrenic. You go to another one and they say you're epileptic. Another one wants to give you a lobotomy.

"I'd like to give those doctors a little talking to . . . but he" -- and she pats Bliss affectionately on the arm -- "he's chickening out. But I'd give my eyeteeth to do that, because I feel so strongly about all the misdiagnoses and mistreatment and the ones that label you as chronically mentally ill. No hope. Incurable. That happened to me over and over again, and I still don't know how or why I kept fighting.

"Hospitals are the worst places," Andrea says. "They treat you in a traditional kind of mode. For example, they'd put me on a closed ward in restraints and I would go even crazier, and they would say, 'Now, see, you're still out of control and we're not going to let you out of these,' and I would just go wilder. Then the doctors would ask me if I saw things or heard things, and I'd always say 'no' because I knew if I said that they'd think I was crazier than I already was.

"I know," she says tartly, turning to Bliss, "you're going to defend your colleagues . . . "

Bliss sighs. It is clearly not the first time they have been down this road.

"Look," he says, "I was ignorant for 30 years. If you'd come to me 10 years ago I wouldn't have known what was wrong."

Bliss concedes that too many cases like Andrea's are misdiagnosed, or just missed, and estimates that 10 percent of psychiatric patients may be multiples. Frank Putnam believes that figure is high. He says there is "no question that it is misdiagnosed and underdiagnosed. But," he adds, "there is hardly any evidence for an actual estimation."

Putnam believes that spontaneous hypnosis "is one manifestation of a process of dissociation, but not the only one." His research at St. Elizabeths has involved, in part, the demonstration of how the different selves in multiple personality disorder can evidence distinctly different brain waves in response to the same stimulus, and manifest different physical characteristics -- visual acuity, allergies, even illnesses, such as diabetes.

He describes an adolescent patient he saw recently who, when one personality emerged, suddenly developed a rash on her face, chest and arms. Her mother said this always occurred when that particular self was in control.

"Dissociation," says Putnam, "takes a variety of forms. One of the issues is that it impairs memory and it is highly linked to trauma. The process that gets activated by traumatic experiences serves to compartmentalize or isolate the memories and emotions that go with those traumas."

In response to a question, he speculates that children who will one day tell a therapist about an abuse and then profess not to remember once they are on a witness stand "may have dissociated under stressful experiences. You always see this spotty ability to access information in these people. It is a core feature of the process."

Andrea can confirm this. She has been serving as a counselor for sexually abused adolescent girls for several years. She is, she says, both amazed by and empathetic toward those unable to "remember" the abuse, to accept that "my loving, wonderful parent could have hurt me."

"It is," Andrea says, "perfectly reasonable to want to hide something like that, to block it out as fast as you can."

"Prism" was written, at least in part, to call attention to the widespread existence of multiple personality disorder and to the need for more meticulous screening of psychiatric patients. But both Andrea and Bliss are surprised at the interest the book is already generating, from the public, from TV moviemakers.

Putnam is willing to speculate on the fascination with the phenomenon, first recalling a CBS producer who was filming recently at St. Elizabeths. "He said, 'Oh, multiple personality disorder -- the only sexy thing psychiatrists are doing these days.' So clearly," says Putnam, "It has some glamor.

"If you look at our culture, you will see a deeply embedded fascination with transformation -- Jekyll and Hyde, Superman, Wonder Woman -- and behind that lurks something else, the issue of the hidden -- werewolves, vampires. It is longstanding, and really goes back to the Greeks -- people turning into animals, gods masquerading as animals or turning people into animals. It is part of western civilization."

Eugene Bliss may be scornful of "the squiggles" of the EEGs and other technologies designed to explain multiple selves, firmly convinced that an innate ability for self-hypnosis is the simple explanation. However, he and Frank Putnam and most experts in the field agree on one major point: The therapy is exquisitely painful for the subject, and alternately rewarding and exasperating for the therapist.

"Remembering," Putnam quotes from a recent book on post-traumatic stress among Vietnam veterans, "is worse than being there."

The selves within Andrea Biaggi made her forget crucial happenings the second she remembered them. At several points she was ready to "go to the hospital, where I belong," and Bliss was ready to throw up his hands and let her.

The book was written two years ago, three years into the therapy, but both Andrea and Bliss knew that even though all the personalities had been fused by then, the work was just beginning.

"It feels almost like an addiction to me," Andrea says. "Whenever I'm in high stress situations, I always get that sense to pull back, pull out of it.

"For example, about two weeks ago I was shopping for this trip, trying things on at a mall, and I smelled some cigar smoke. And because of all the associations with cigars smoked and used as torture implements by her father , it was -- pow -- just that fast that I went into a full-state panic.

"The difference this time, though, was that I was able to sit down, and I knew right away it was the cigar smoke that had done it. I calmed myself down and I got myself back together and then just went back to what I was doing.

"Knowing I can control it, that's given me my life back."

She is pensive, but then Bliss adds that "Andrea was teaching me a lot all that time." Turning to her, he says, soberly, "Thank you very much."

Andrea bursts into gales of laughter.

"I'll send you my bill," she says. And laughs again.