POSTCARDS FROM THE EDGE By Carrie Fisher Simon and Schuster. 221 pp. $15.95

Carrie Fisher was barely out of diapers when her father, Eddie Fisher, left her mother, Debbie Reynolds for Elizabeth Taylor. It was the most publicized marital split in recent history, and installed young Carrie as a charter member in the Sigmund Freud couch potato set.

A so-so acting career ("Shampoo," "Star Wars," "The Blues Brothers") was followed by a stormy 11-month marriage to singer-songwriter Paul Simon, which was immediately followed by a month in a drug rehabilitation clinic. (Percodan and acid.)

Happily, Fisher has conquered her demons with a wonderfully funny, brash and biting novel "Postcards From the Edge," the most startling literary debut since Jay McInerney's "Bright Lights, Big City." Destined to become a cult classic with the "Saturday Night Live"/Saab Turbo set, Fisher's assortment of searing one-liners and film-set psycho-babble reveals Hollyweird at its wackiest: Rodeo Drive, vegetable peel facials, swarthy Czech film directors, rock stars with cocaine habits, agents in Bentleys, women in T-shirts saying, "Some of us are becoming the men we wanted to marry," and producers who protest that sleeping with four girls a week does not make them "womanizers."

This is a laugh-out-loud book. A girl's book, fer shur. If Fisher has any sense, she will stop trying to get Daddy's attention as an actress and turn her considerable talents to chronicling the Bel Airheads who float through the palm-treed air like pollen.

Meet Suzanne Vale, a suicidal young actress and Carrie's alter ego, who swallows a bottle of Percodan and winds up in a drug clinic, having her stomach pumped. "It's like I've got a visa for happiness, but for sadness I've got a lifetime pass," Fisher writes. "I shot through my twenties like a luminous needle, blazing toward my destination: Nowhere."

The cocaine and opiate addicts make up a "Cuckoo's Nest"-like crew, and along the way Suzanne meets Alex, a would-be screen writer who bails out of the clinic only to be found coked up in a motel room, a pharmaceutical Cuisinart stuck on "Pulse." Or the addict who played his Walkman so loud at breakfast "we could hear the music through his nose."

Terminally glib, Suzanne gets flowers from the guy who pumped her stomach ("I'm tempted to marry him just to be able to tell people how we met"), complains that "instant gratification takes too long" and wonders if the inmates of the drug camp shouldn't be making "drug lanyards." She worries about her skin. She worries about her weight. She hastily leaves a dinner party when she overhears two women talking about her figure: "I'm retaining water for a couple of people, and I've got to return it by midnight."

Fisher's descriptive powers sometimes lapse into slumber-partyisms (sushi is described as "whale gums" and oysters are dubbed "elephant boogers") but for the most part, the author's voice is keenly perceptive, surprisingly sentimental. She is on the biological Titanic and sinking fast. Like many of her contemporaries, she will probably go down with the ship.

"I was born imagining myself with an apron on, with pies cooling on the window sill and babies crying upstairs. I thought that all that stuff would somehow anchor me to the planet, that it was the weight I needed to keep from just flying off into space."

Once released from the rehab clinic, Suzanne wins a film role, has a masochistic fling with a producer, then meets Jesse, a patches-on-the-elbow, corduroy-clad writer who provides the security she has been searching for all her life.

My only criticism of the book is with Jesse. Like Alan Bates in "An Unmarried Woman," he's just too good to be true. He comes in so late, and is so hastily sketched, it's a disappointment rather than a redemption. As if all that pain and suffering could be alleviated by the love of one good man who is smart because he reads newspapers. Was it Nora Ephron who said that getting married was the closest thing shrinks have to a cure?

"Suzanne was convinced that now something nice and regular was happening to her, she was going to die. Whereas she used to hasten her death through substance abuse, she now feared for her life because she had reason to live it."

In any case, Carrie Fisher deserves a happy ending. Mike Nichols has reportedly bought the film rights to "Postcards," and maybe Carrie will even get to play herself.

She was born for the part. The reviewer is a staff writer in the Style section of The Washington Post