It had been a bad day at the Bethesda real estate agency where Truddi Chase worked and all she cared about was getting home. As she drove alone in her car along Rockville Pike, she said she felt "a million pins and needles in my hands and arms . . . like going under anesthesia." She said a voice kept saying, "No, we want coffee."

As the episode continued, Chase said she suddenly was watching herself from outside her own body, as if she were viewing a movie: "There were two people wrapping themselves over, under, around and in me." At first she giggled at what seemed an absurd apparition, but moments later, against her will, she pulled into the parking lot of a 7-Eleven. "I didn't want coffee, they did," she recalls.

The 44-year-old Chase caught her reflection in the glass window of the store. She remembers seeing a smiling young woman with short hair and a bouncy walk. Then she saw herself become a broad-shouldered man with a stern, menacing expression. "He was 12 feet tall and black," Chase said.

Chase said that the three of "them" went into the 7-Eleven. While the hulking "man" stood guard, "the women" bought a single cup of coffee, put it in a bag and walked out.

That was just over two years ago, and it was the first time that Chase recalls encountering those other entities, whom she came to call "Miss Wonderful" and "Mean Joe Greene."

Chase, who has since left her job in real estate and now supports herself as a freelance artist, is one of perhaps hundreds of people suffering from a condition known as multiple personality disorder (MPD). First popularly portrayed in the movies "Sybil" and "The Three Faces of Eve," MPD is a condition that is believed to develop primarily in people who were severely abused as children.

Healthy people have different moods and exhibit different aspects of one personality, but they usually remember their changing moods. Such changes are more severe in people with MPD and those people often do not recall their actions or emotions. Chase and her therapist say Chase may experience 40 or more personalities.

Chase says she cannot remember years of her life; often she does not recognize the clothes hanging in her closet. Sometimes she finds food in her refrigerator that she doesn't remember buying; and on several occasions, she has "awakened" and found herself in unfamiliar surroundings, carousing with people she does not recognize.

Chase, who says that she has not been in contact with her family in more than 20 years, was born into a staunch Irish Catholic family and lived on a farm in the Northeast. During her childhood, from her first memories to her teen years, Chase says she was stalked by a man who sodomized and raped her repeatedly.

About 90 percent of reported MPD patients are women, according to Dr. Frank Putnam, a psychiatrist at the National Institute of Mental Health. Working out of St. Elizabeths Hospital, he has done considerable research on the disorder. Eighty percent of all patients with MPD have been abused physically as well as sexually as children, Putnam has found.

Generally, that abuse comes at the hands of a family member, making it even more traumatic, says Chase's therapist, Robert A. Phillips Jr., a family therapist with the Human Sexuality Insititute in the District.

The syndrome, Putnam says, tends to develop as an extraordinary coping mechanism in the face of severe stress. Multiples create new personalities to help absorb their shock and to manage their various emotions.

"I want understanding for multiples," Chase says. "It's not a thing to be ashamed of; we're not freaks . . . . Once we were alerted that sexual and physical child abuse was so rampant in this country. . . we found that describing our own pain and chaos benefited some of those persons who, like us, were convinced that they were insane."

The Truddi Chase that comes across most often is a striking and vivacious woman, given to outspoken, witty and poetic phrases. She is a slender but big-boned woman who wears outfits that have been carefully matched with accessories. Her hair is colored blond and her fingernails are always polished in a muted pink.

Chase carries a shopping bag with her just about everywhere. It contains whatever business materials she may need for the day, and items such as several stuffed animals and a treasured box of crayons for the "children" within her. Sometimes, when she is frightened or upset, Chase pulls out her toys and cradles them in her lap.

The disorder is not new. The first case of MPD was reported by a New York physician in 1815. About 30 cases were reported between 1815 and 1965, but according to medical literature, the number of reported cases surged in the late 1960s and early 70s.

"They tend to be very bright people," Putnam says of multiples, adding that they seem to excel in art, music and writing. "I know of a number of multiples who hold very high-level postions and are able to function while being very disturb-ed."

This article was written after numerous conversations with, and observations of several therapy sessions between, Chase and Phillips.

Phillips, who has worked extensively with sex offenders and their victims in Montgomery and Prince George's counties, says Chase's stories are consistent each time she tells them, and that he has no reason to doubt their authenticity.

Over the past year, Chase has decided to speak out publicly about sex abuse and about her multiple personalities. She has appeared on local television programs, describing the abuse she encountered as a child. She has even met with a group of men who have abused children to explain to them the impact of their deeds.

The man she identified as her abuser, contacted by The Washington Post, said "she Chase has such a line of bull."

Chase said the man would follow her into the cornfields and spy on her. "You never knew where he was," she said.

Once when she did not comply with his sexual demands, he tied her ankles, hoisted her on a pulley and swung her upside down, across the ceiling of a barn as she screamed in terror, she said. On another occasion, she told Phillips, the man put her in a small, open crate attached to a rope, lowered her into a dank well and threw snakes in on top of her.

According to Phillips, Chase escaped into the dark, secret world of her mind, a world she is just becoming acquainted with, because, as Phillips explained, these memories have been kept secret for years by Chase's various personalities.

Before Chase was aware of her inner turmoil, she would erupt into fits of rage that she could not explain, which finally, about 10 years ago, destroyed her marriage. Until recently, Chase felt too confused to take on full-time responsibility for raising her daughter, who is now 16, and left the daughter with the girl's father. Chase was referred to Phillips for therapy in 1980 and together they have begun to unravel her nightmare.

Chase's different personalities have separate thoughts and emotions, and different physical features and idiosyncracies, Phillips says. Phillips has been able to "meet" most of the personalities and some have been captured on videotape.

In a videotaped session in January 1981, Chase sat in a chair facing Phillips. After a few moments of conversation, she looked down into her lap and began to whimper. In a child-like voice, she told Phillips that she was wearing a white dress and little white shoes. "Yes, it's white . . . with dots," she described the dress. Then she shook her head vigorously. "Little red dots," she said playfully.

Phillips asked her name and she said slowly, "Lambchop. Lampchop With Mint Jelly, that's my name . . . I am very small . . . the others are big . . . they hurt me."

Suddenly the child face clouded; Chase pulled at her hair and began clawing at the air. She appeared to be terrified of something. "Someone spoiled the Easter baskets," she said flatly.

"Who did?" Phillips asked.

She moaned, shook her head and stared at her palms spread open in her lap. "Him," she mumbled, unable to say more.

Time after time, people close to Chase, including Phillips, have witnessed such striking identity changes in Chase. Phillips says that the woman he sees most often these days is a gifted and energetic woman, but that that person is probably not the "real" Truddi Chase. He suspects that the real Chase is a quiet, wistful and tortured woman who was captured--half adult, half child--in that early videotape.

The changes can be quick and striking. In one session where Chase was talking about her mother, she was reminded that she is also a "mother." Chase hates that word. She looked down for a moment, massaged her temples as she often seems to do when another personality appears to emerge. She began to breathe rapidly, reared back in her chair and in a hoarse voice snarled, "Don't bet on it, honey!"

Chase has written lengthy descriptions of the "people" who conduct her life. Most of them are female, but some are men and several are children, whom Chase calls the "little ones." She refers to them all as "the troops" and to herself as "we" instead of "I." The troops include "Miss Wonderful," who is afraid of nothing and for whom life is "a bright yellow daffodil . . . there is no sex and no pain."

There is a tough, demanding businesswoman with a husky voice named "Ten-Four," and a pitiful creature called "Rabbit" who harbors all of Chase's physical pain and who has no voice except a piercing wail.

"Sewer Mouth" is the person who speaks up for the mannerly Chase when she is feeling particularly angry or obscene. "Twelve" is a young girl, who, according to Chase, "dances, which Phillips' patient does not, and her favorite foods are BLTs, YooHoos and strawberry sodas."

"Ian" is a heavy-set, short-tempered Irishman who lectures at length in a heavy brogue. Ian tends to surface around men and engages them in heated philosophical discussions. Chase grumbles that she hates driving after Ian has emerged because "he" always pushes the car seat back too far for her to reach the pedals.

Chase insists that there are advantages to having multiple personalities. "They" have boundless energy and are always on the go, she says. Some can "sleep" while "others" are working.

Chase works almost round-the-clock. Last fall, she illustrated a training manual showing teachers how to teach children in non-sexist ways. During the winter, Chase was busy trying to convince the U.S. postage stamps committee to accept her design for a stamp called "Stamp Out Child Abuse." A final decision on the stamp is pending.

Currently, Chase has completed a draft of a book about her life, a project that Phillips says has been very useful in unlocking and dealing with hidden fears.

But life with "the troops" can be distressing. Recently she had to fill out a lengthy legal document and get it into the mail. "We got into the car, drove to the post office and boom, we were in the grocery store," she said. She left the store quickly, got in the car and began crying. "We do not remember mailing it the form ," someone in the car said. But then another, calm voice said, "Don't worry, we mailed it."

"Somehow," she says, "we manage to get things done."

According to Putnam, the most widely used method for treating multiples is called integration. The therapist assists the patient in becoming aware of all of the personalities and then tries to get the various roles to meld into one.

Chase doesn't like this idea. In fact, she had a T-shirt made that says, "2-4-6-8 We Will Not Integrate." Chase says she's beginning to appreciate her many selves and feels certain that integration would "kill us off."

Phillips has decided not to force the issue, because he believes Chase is doing well. "The way I determine her progress is that they the troops are now able to deal with life crises without being immobilized or having to hide," he says.

Chase also thinks she has made progress. "The difference between now and two and a half years ago is the difference between the year 1 A.D. and the year 2000," she says. "We no longer tremble like a leaf in the wind."