You may not have to be crazy to work in television, but after a few weeks, you will be. Additional proof of this, as if any were needed, comes in "Saturday Night: A Backstage History of 'Saturday Night Live,' " a fascinating and lurid new book about the landmark comedy program's 10 tumultuous years on the air.

A more disagreeable, egomaniacal, selfish and dissipated crowd you would not want to meet than the changing casts and staffs of the show, at least as authors Doug Hill and Jeff Weingrad portray them. It appears they all took turns behaving like swine.

Everyone knows, thanks to "Wired," that John Belushi was a doper. He was also, according to this book, a raging misogynist who urged repeatedly that all the women writers on the show be fired. He made an obscene disparaging remark about Lily Tomlin just before a show she guest-hosted, and according to the book had to be calmed down with "a toot of cocaine" as he ranted and raved in a hallway outside the studio. He comes across as a petty and vindictive little man, but in this company, he was hardly out of place.

Even the seemingly well-moored and likable Bill Murray went on wild ego binges, it appears, once getting into a fistfight with Chevy Chase after Chase had left the cast and come back as a guest host. Murray is alleged to have shouted, as he flew at Chase with his fists, "This is my show now!" It sounds like something he could only possibly have said as a joke.

Everybody hated everybody else. In the show's later years, Joe Piscopo and Eddie Murphy became allied and ridiculed others in the cast. Then when Murphy became a big star, the authors write, Piscopo became insanely jealous. A writer is quoted as saying, "It broke his heart to walk down the street with Eddie and have everyone yell 'Eddie!' and pass him by." Show business; it's ugly.

Although "SNL" humor would ridicule sexism during its first five years, the writing and performing staffs were dominated by sexist neo-macho males. Gilda Radner developed bulimia during her five years on the show, the authors write, and Laraine Newman became anorexic and drug dependent, so that when her five years ended, she left the show "all but shattered."

Jane Curtin, it appears, led the sole life of quiet normality. She now costars on the CBS hit sitcom "Kate & Allie."

Drugs were everywhere. Chase used a real joint for a prop on camera during a marijuana sketch and, the authors say, Garrett Morris spent his last couple of seasons on the show free-basing cocaine in his dressing room. Al Franken and Tom Davis, writers in the early days and coproducers of the program now, used LSD on the premises while writing a Nixon sketch, according to the book. The band's dressing room was such a recreational drug center that it became known around NBC as "the departure lounge."

Even founding producer (now executive producer) Lorne Michaels allegedly put finishing touches on the show's format, back at its creation, while munching hallucinogenic mushrooms during a weekend at the Joshua Tree Inn, a motel in the desert outside Los Angeles. Michaels, who has not read the book ("I still haven't read 'Wired' "), says from New York that the mushroom story is baloney, although he admits he once did eat mushrooms. "I've read five different versions of five different people who say they were with me when I saw this vision," he scoffs. "I did do mushrooms once, but that stuff about the weekend in the desert is all bull."

Michaels' longtime agent Bernie Brillstein has read the book, Michaels says, and told him it is "in general, accurate." But Michaels says people like Radner and Dan Aykroyd refused to talk to the authors, and that many accounts of backstage scandals are secondhand, possibly from people who were "frustrated" then and bitter now.

"What surprises me," Michaels says, "is who talked, and how loud their voices are."

Not everything in the book is mean-spirited by any stretch. Reprints of script highlights tend to fall flat, but plenty of corridor and dressing room gossip is benign. When Richard Pryor guest-hosted the show, it is revealed, the network was so nervous that it insisted the live program go through a seven-second delay before it hit the airwaves, and Michaels reluctantly agreed, though he wouldn't have dreamed of letting Pryor know.

There are stories of guest hosts who got drunk or disappeared just at show time, and of how Michaels and the others detested such guest hosts as loopy Louise Lasser or Milton Berle. The Berle show has been withheld from the rerun syndication package; Michaels hated it that much. Hell's Angels dropped by the show's 17th-floor offices in the RCA Building one day, the authors recall, and a censor once objected to a sketch about a nerdy high school staging of the Nativity story by exclaiming, "You can't give noogies to the Virgin Mary!"

What stands out, however, are the tales of ugliness, insensitivity and boorishness. Writer and self-styled cultural outlaw Michael O'Donoghue seemed to delight in malicious humiliations. He had "a vicious temper," the authors write, and loved to pull telephones out of walls and smash them across a room. In the show's later years, he proposed to producer Dick Ebersol not only that announcer Don Pardo be fired, but that he be fired on the air, at the start of the show's seventh season.

With all the obvious doping going on in the "SNL" offices, and for all the controversy the show generated, particularly in its five hot years, one wonders why NBC, an organization the writers went to great lengths to insult and denigrate, put up with all this. Why? Because "SNL" carved out lucrative new advertising territory and lured a video-alienated audience back to the tube. It wasn't just a hit. It produced, according to an unnamed NBC executive quoted in the book, "the best demographics in the history of commercial TV."

NBC Chairman Grant Tinker says he has not read the book and suggests he is not an "SNL" fan. But NBC Entertainment President Brandon Tartikoff says from his office in Burbank that he has read about half the book, "from when [former NBC chairman] Fred Silverman got there, to the end. Just the era I am familiar with." And how accurate would he say it is? "Ninety-four percent accurate," he says.

"They really put this show under a microscope," Tartikoff says. "They did a good job of reporting what I know to be true. It seemed to be incredibly accurate."

What about the book's tales of incredibly furious warfare during the show's first post-Michaels year, the short-lived reign of producer Jean Doumanian? "Had I known what was going on at the time it was going on, I think I would have done something to correct the course before the show even went on the air," says Tartikoff. "I really had no idea there was that kind of division and chaos."

According to the book, one writer during that era claims he was threatened with death by a producer's bodyguard. Tartikoff says, "When I read that, I thought it would make a good scene in a 'Network'-type movie."

The book alleges that wholesale drug-taking in the "SNL" offices became rampant again when Ebersol took over as producer. "I never knew that to be true, and I hosted the show for a week myself," Tartikoff says. "Not that they would have done anything in my presence, of course." Tartikoff appeared at the start of the premiere show this season, in a sketch about conducting a urinalysis of the show's new cast to make sure it was drug free. The sketch went over so badly that Tartikoff has had it removed from the show, so that it will not be seen in rerun.

Michaels is not so much worried about what effects the book will have as he is worried about the ratings for this season, the season he returned to run the show again. Ratings have been so-so, and the show's writing has been, for the most part, groaningly bad. The programs tend to begin on a high note (Ron Reagan's "Risky Business" dance, or, last weekend, Jay Leno's brilliantly hilarious monologue) and then nose-dive. The new cast does not seem possessed of any kind of playfulness. Key cast member Randy Quaid is roughly as funny as a 1040 form.

Still, the show remains live and topical and ambitious, hardly justifying the recent clamor by some TV critics, including TV Guide's, that it be yanked off the air immediately as a disgrace to all mankind -- TV Guide's man calling it "tasteless," which is what TV Guide thought of it even during its glory days. The same critic gave rave reviews earlier in the season to such stale Hollywood fare as "Spenser: For Hire" ("a very good show") and the Alan Thicke comedy "Growing Pains" ("thoroughly entertaining").

Aging humorist Henry Morgan released to the press a letter he wrote to Tartikoff demanding that the show be canceled. Michaels says he is baffled by the hostile assaults, though he was interested to learn that Henry Morgan is "still alive."

The show is "too host-dependent" now, Tartikoff says, "so that if you have a host like Harry Dean Stanton, the show tends to tumble down around him." But he says he is pleased with the improvement shown since the premiere and with the fact that Michaels has returned. "I'm glad I'm with Lorne, and I think that by March and April the show should really start to click. If the shows continue in the Ron Reagan vein, I'd say we'll renew it early and beat the drum about it."

Tartikoff also says that mediocre ratings or not, "we are making money" on "Saturday Night Live" -- that, indeed, "late night as a day-part is having an incredibly profitable year," led by the smash hit David Letterman show.

Letterman rides the cutting edge in TV comedy now, but "SNL" rode it for years, and blazed the trail; it introduced the idea that commercial network television could be hip. And daring. Michaels says that even if the book makes producing "Saturday Night Live" sound like a living hell, he doesn't remember it that way himself.

"There was this closed society, in sort of a state of grace, for about 2 1/2 of those first five years," he says. "There was virtually no grief. No really major problems. When the Hollywood part happened, the big movie offers, and the big money came in, it sort of changed everyone's status. Billy Murray gets $7.5 million a picture now. Chevy gets $4 million. That's bound to change people."