Few advocacy groups have aroused as much controversy in mental health circles as the Philadelphia-based False Memory Syndrome Foundation.

The purpose of the 2-year-old foundation, according to its literature, is to publicize and document "a new phenomenon" involving adults, typically affluent, educated women in their thirties who go into therapy and suddenly remember abuse that never occurred.

Despite its name, "false memory syndrome" is not a disorder recognized by psychiatry or psychology. Nor is there a foolproof clinical way to distinguish true memories from false ones. In a letter published last year in the APS Observer, a journal of the American Psychological Association, 17 internationally respected psychologists, some of them memory experts, strongly objected to the user of the term.

"Many children," the letter states, "are sexually abused. And, unlike lab scientists who carefully construct events and measure the degree of distortion in memories of the events, few cases of child sexual abuse remembered in adulthood are verifiable one way or the other. In the vast majority of cases we will simply never know."

More than 11,000 people have contacted the foundation so far, according to its executive director Pamela Freyd, who founded the group as a way of coping with the memories of incest that have ripped apart her family.

In 1990, her older daughter Jennifer, then 33, a psychology professor at the University of Oregon who specializes in the study of perception and memory, began psychotherapy. Shortly afterward she accused her father, Peter Freyd, a mathematics professor at the University of Pennsylvania, of incest. She accused her mother of permitting the abuse to occur and then of denying it.

Jennifer Freyd has not filed a lawsuit against her father. She no longer speaks to her parents, nor, says her mother, does her younger sister, a college professor who has said she believes Jennifer.

Jennifer Freyd declined to be interviewed. Through an assistant she said that a paper she delivered last summer at a mental health conference reflects her views.

In it she says that her father was severely alcoholic throughout her childhood, that her parents are stepbrother and stepsister, that her father was sexually abused when he was 11 by a male family friend, that her father kept a model of his genitals in the family living room and that when she was 11 he taught her to kiss "like an adult" for a part in a school play. She writes that he first molested her in the bathtub when she was about 3; she says the abuse continued until she was 16 when he raped her shortly before she left for college.

Peter and Pamela Freyd have repeatedly denied their daughter's allegations of sexual abuse. In an interview, Pamela Freyd said that her husband was sexually abused as a child and that in recent years he kept a model of his genitals in the living room that she says he made in an "outrageous" moment. Peter Freyd, in an unpublished account of his family's experiences, says that he doesn't remember teaching Jennifer to kiss for her role in the school play. "I certainly didn't french kiss her," he stated.

Pamela Freyd says that in 1991, after their daughters refused to see them, they turned to their friends, many of whom are psychiatrists and academics, for support. Aided by several favorable columns about false memory in the Philadelphia Inquirer, Pamela Freyd started the foundation in March 1992. It now has a toll-free telephone line and an office in downtown Philadelphia from which the group provides glossy press kits containing reprints of favorable articles. Pamela Freyd also writes and edits a monthly newsletter.

The foundation's scientific advisory board is studded with well-known names in the fields of psychiatry and psychology, few of whom have much clinical experience treating trauma victims. Board members include psychiatrist Martin Orne of Philadelphia, an expert in the clinical uses of hypnosis; Paul R. McHugh, psychiatrist-in-chief at Johns Hopkins; and Elizabeth Loftus, an expert in the fallibility of eyewitness testimony from the University of Washington.

Minnesota psychologist and minister Ralph Underwager resigned from the board last year following controversy about his remarks to a Dutch magazine for pedophiles. Underwager called sex with children a "responsible choice" and said that pedophiles "can boldly and courageously affirm what they choose."

Freyd says that Underwager resigned because the interview was "so open to misinterpretation" and because too much time was spent answering questions about it. "Our focus is memory, not pedophilia," she says. Underwager's wife remains on the board.

But to some mental health experts, Underwager's views and the foundation's repeated attacks on psychotherapy raise disturbing questions. Stanford University psychiatry professor David Spiegel, for example, declined an invitation to serve on its board. "I think they're going after psychotherapy as a profession," says Spiegel, who specializes in treating trauma victims and is an expert in hypnosis. "The whole way that group operates, I don't like."

"I personally know some members {of the foundation} who are aggrieved parents who have been falsely accused, including one guy I'd leave my kids with," he says. At the same time, he says he believes the group provides "a great cover for pedophiles. And it feeds into this cultural need to deny that bad things happen to children."

Pamela Freyd sees things quite differently. "It's certainly possible" she says, that there are pedophiles in her organization. "If you've been contacted by 11,000 people . . . I don't know the truth or falsity of the reports" because they haven't been independently evaluated.

Incest is "one of the most heinous crimes one person can commit against another," she says. "Parents are being accused of criminal acts, based on so-called repressed memories and this theory has never been scientifically proved."