SYLVIA FRUMKIN, who is the subject/heroine of this book is a clever, poignant, crazy, pitiful, engaging, enraging, hysterically funny slob. Sometimes all at once, but more often sequentially or in combinations of merely two or three of these characteristics. The clinical description of her condition is apparently "schizophrenic," although she is endlessly diagnosed and rediagnosed by professionals in the course of this book which covers 17 years of her life-- from age 15 to 32--in and out of mental institutions in New York state. At the end, we leave her in a relatively promising state of remission. But as we have seen these states appear and (just as quickly) disappear, we go away with a sinking feeling about the ultimate prospects for "Miss Frumkin"--as author Susan Sheehan insists on calling this woman most of the time, a kind of thoughtful covering garment of dignity and respect she holds up for one whom we are repeatedly to see naked, mad, abused and abusing, unimaginably degraded.

Susan Sheehan has committed an extraordinary act of journalism here. She spent much time with Miss Frumkin, conversing with her, observing her on the ward, studying her records and history. She brings relentless, intelligent attention to bear on a particular case, a journalistic practice that almost always results in new and disturbing insights into those mindless generalities and prejudices and certitudes we tend to carry around with us. I am not fit to judge the merit of the argument over whether Miss Frumkin was or wasn't given proper dosages and combinations of the different drugs currently used to treat her kind of psychosis. And the same is true of the dispute over other elements of her treatment. But you don't need to be a specialist to get the larger message from this saga. For Miss Frumkin, the subject, is as relentless in her way as Susan Sheehan is. She won't let you get away with anything. She won't let you alone. She is out to disprove every comfortable, cop-out theory you ever had about her kind and her condition and what we do for both.

It is true that the book reveals some terrible lapses in institutional conduct, for instance, and some dangerous shortages of money, expertise and common sense among those charged with the care of Miss Frumkin when she is at her most violent or deranged. But I was struck by the reverse of this as a general matter: the enormous number of individuals and groups and institutions that have taken extra initiatives and invested money and energy to try to help Miss Frumkin--relatives, church folk, doctors, case workers, hospital attendants and administrators. She has been the beneficiary, if that is the word for it, of all those many reforms and bright ideas we editorial writers like to pronounce the good and self-evident solution: halfway houses and rehabilitation programs and vocational training and God knows what all for nearly two decades. What we learn is humility, that there are some human conditions and complexities we can't "fix" with a bright idea.

Then there is Miss Frumkin's family, like their ungainly, soup-slurping daughter, a tangle of frailties and oppressions we cannot hope to straighten out with a little counseling or help or even a lot of both. They are at once victims and villains as, I suppose, most families of people like Miss Frumkin are. Harriet and Irving, with their super-achieving, remorse-ridden older daughter Joyce and their excruciating psychotic daughter Sylvia who is ruining all their lives (and yet satisfying something not-so-pretty in them too)-- they are almost a parody of the parody of a type of mutually destructive Jewish family so widely and damagingly written about by its angry sons and daughters over the years. Not just the Jewish family, either. Reading about Irving Frumkin, I thought of the pathos of the tightwad father in Eugene O'Neill's Long Day's Journey into Night, who finally so wanted to relax the catastrophic meanness that had cost him so much with his son, but couldn't. Just so, Mr. Frumkin can't bring off the magnanimous or loving gesture with the daughter he wants so desperately to help. Again and again he compulsively takes away what small, normal pleasures she can enjoy for the sake of saving a few cents. Mrs. Frumkin wins a special place in the annals of self-centered and insensitive mommahood for many things, not least of them her remark when she learns that a beige poncho she bought for Sylvia has disappeared. "It isn't enough that Sylvia has lost her mind," she says. "She has to lose all her clothes, too."

Yet they are tragic and cannot deal with a daughter who confounds prediction, analysis, and cure. We see Miss Frumkin punching, bashing and otherwise battering people in the institutions where she is confined. She paints her entire face with lipstick, gets herself up in outlandish attire. Her relationship to reality, even in her more pensive moments, is weird ("she . . . got up, and walked toward the mural on the dayhall wall . . . 'Is this a nuthouse?' she asked the unicorn in the mural.") She addresses unseen presences, believes her luncheon tablemates in the institution are Mary Tyler Moore, Jesus Christ and Barbara Walters, and will tell you God's phone number (JE 333, in case you wondered). She is, physically, truly piggish. Yet one likes, even respects her in many ways and is also unhinged by her.

What you like is her unyielding resistance, her rage at her condition to the extent she perceives it, which is a real if intermittent insight. From within the Bedlam-like environment she inhabits, she speaks in a kind of epigrammatic idiom that has an insane wit to it, reminding you subliminally of some modern poet or clever graffiti writer or even Lear's fool: "Bess Myerson was originally the Statue of Liberty," she tells no one in particular. "The moon is made of cigarettes. A tobacco leaf just jumped out of my hair. . . . A fly is a teen-age wasp."

What is this world she lives in? A pop-cultural mishmash for one thing ("I first met Geraldo Rivera when I was in Elmhurst. John Travolta's father is the Shadow. I think the Cowardly Lion was secretly married to Judy Garland. . . . I want to have my own show . . .") Miss Frumkin's fantasies keep recurring as parody too, as commentary on the loony world the rest of us inhabit. She is mad and then she is not mad. You occasionally sense something sly, almost deliberately fugitive and self-protecting in her madness. And she is, as Susan Sheehan observes, rather more engaging and attractive to many people when she is at her most psychotic--and even perhaps more comforting to herself. "You know," she says, in a period of clarity, "it was fun believing some of those things I believed, and in a way I hate to give up those beliefs. I'll miss having those fantasies. There's a charm to being sick. I like to be in the twilight zone of the real world."

Miss Frumkin's tale, as told by Susan Sheehan, is a tale of human weakness, will, strength, failure, promise and futility. This is a brilliant, terrifying book.