When a young mother became frightened by obsessive thoughts of murdering her infant daughter, she went to see California psychologist Harvey Mindess.

"Naturally," concedes Mindess, "this was not too funny." But after a couple of visits, he became convinced there was no way the mother would harm the girl.

At the next session, he used a new approach. "I walked out to the waiting room and said, 'Did you kill the kid yet?' "

Incredulous, the woman did a double take. Then she laughed.

"It cut through the issue and said, 'Look, we both know you're not going to kill the kid, so let's get on to more important business,' " recalls Mindess with satisfaction. "E.B. White said humor at its best is a kind of supertruth. It helps you expand your perspective."

A cartoonist who draws on real-life incidents, a Presbyterian pastor who sometimes clowns his way through rituals, a 27-year veteran of stand-up comedy, a writer helping hospitalized teen-agers remember their funny bones, and Mindess, who teaches humor at Antioch University in Los Angeles: all have integrated laughter directly into their work. And all consider their lives richer -- not to mention funnier -- because of it.

"We are no less troubled than anyone else," says Mindess, "and the fact that we know a lot about humor doesn't make our lives a bowl of cherries. But when any of us are in a crisis situation, we might be more apt to eventually resort to humor as one of our coping devices -- more likely than other people, perhaps."

Take New York cartoonist Gahan Wilson and the escalator, for instance.

"One time I was on an escalator in Bloomingdale's, and there were these two nuns, and one of them got her habit caught," he says. "The escalator stopped, but it instantly gave me the idea for a cartoon showing an escalator sucking in quantities of people, really drawing them down into the works."

The punch line: One floorwalker says to another, "God, it's been one of those days."

And then there was the time Wilson was driving on the expressway and matters got out of hand.

"Everything was mechanical in the car -- it had an automatic shift and everything. I got to a tollbooth, and there was a mechanical moneytaker. I clawed out some money, threw it at the slot -- and missed. So I opened the door and leaned out . . .

"Then the car started moving. There I was, caught between these machines. And you can never challenge those things because you never know what they've got stored up in the works against you. It was a wonderful moment. I'm sure it'll turn up in a cartoon."

For Wilson, 55, finding the humor in daily life can be as simple as reading the newspaper.

"Any newspaper is a godsend to a cartoonist, a constant deluge of hilarious stuff," he says. "Most people take it all overly seriously, but it gets so bizarre, I don't see how they can keep a straight face. I'm very grateful to the politicians for behaving as they do. It gives me my livelihood."

And it's an amusing life, says Wilson: "While some people don't get the jokes, it's very difficult for me to get the serious." Every once in a while, however, there can be trouble. The worst time people didn't get the joke was about 20 years ago, when he drew a desiccated Santa clogging a chimney.

"That got more angry mail than anything I ever did. You can mess around with religion, but when you kill off Santa Claus, there's an uproar. You never know."

Tom Niccolls knows a little about messing with religion. A Presbyterian chaplain at Hiram (Ohio) College, Niccolls sometimes dresses up as a clown to preach a sermon or perform other religious duties.

"Many people find that a ritual that is repeated in the same way becomes routinized," he says, "so the clown has opportunities to break through to fresh meanings. For example, in most Christian liturgy the bread and wine are spoken of as the gifts of God."

*Thus, Niccolls the clown may transport the bread and wine in a large gift-wrapped box. He'll open the box, discover with great delight the contents, and mime a feast. "It's a way for people to realize again the meaning of the words they have heard so many times."

* The decision to adopt a clown face for Niccolls, 56, stems directly from his own experiences. A veteran of campus life of the '60s -- and the discouragement that eventually resulted from the civil rights and the Vietnam war protests -- he was also going through a "mid-life crisis, and oppression began to hang heavily on me. The clown represented the spontaneity that you sense you're losing track of in your forties."

* He doesn't, of course, do every sermon in clown face. "Occasionally there will be persons who are uptight about this. People bring such expectations to the formal worship that sometimes a radical challenge can get in the way of their just enjoying it."

While grandparents and grandchildren are often in touch with his spirit, it's the middle-aged, particularly men, "who are instead very caught up in the successful competency style of life. The clown challenges that, and represents the human tendency to goof it up, fall on our faces, and then go on."

Tom Smothers also knows how to keep going, in spite of comic highs and lows ranging from a hit national TV show from 1967 to '69 to being told in 1983 his was the only act at the Wild Animal Park in San Diego that could get the giraffes' attention.

"Most comics have a certain kind of affliction," says the elder half of the Smothers Brothers. "Humor is the way we cope. I don't think there's any totally sane or rational people who deal in comedy."

*The Smotherses have been coping this way since 1959. "I could have been a thief, or a criminal," says Tom. "I always liked creating chaos. But now I don't think we'll ever stop doing it. One of the things we get out of comedy is working on our relationship all the time. It's like therapy."

Their situational comedy routines, performed on the road 10 months a year, are drawn from mutual affection mixed with healthy, genuine disagreement. "People wonder how we've gotten along so long. Dickie always says it's like an old marriage: a lot of fighting and no sex."

The brothers also are partners in a small winery, which produces -- of course -- Smothers Brothers Wines. "Wine, like comedy, is also very subjective," says Tom, 49. "Neither are necessary, but they add that extra joy."

Which may mean extra life. "We know now that laughter is therapy for people. Comics tickle people's minds. I consider myself a kind of brain surgeon."

Best known for advancing the idea of humor as a vital element in the healing process is former Saturday Review editor Norman Cousins, whose use of laughter helped him recover from a degenerative collagen illness.

"Laughter," he says, "is a form of internal jogging -- when you do it, you move your parts around, bring in more oxygen. You'll feel better, I promise."

When Cousins was hospitalized in 1964, the only way he could watch laugh-provokers like "Candid Camera" and the Marx Brothers was by renting a projector. Inspired by Cousins, Bea Ammidown, a 48-year-old writer, decided to make it easier for patients at Children's Hospital of Los Angeles to find humor. She came up with an organization called Humorx and a Laugh Wagon, a cart on which she piles a VCR, television, audio tapes, books and magazines.

"When we show them a good program, kids in wheelchairs bump up and down, nurses crowd into the room, kids are riveted to the screen," she says. "They don't really seem aware of the tubes sticking into them. They light up."

* Sometimes, the ones who appear to need humor the most are not the patients, but the parents: "The parents often look sicker than the kids. Sometimes helping the parents helps the kids."

And that's her whole point. "When I see the kids laughing, I feel good -- that some higher purpose is accomplished. You don't have to be laughing to be healed, but it certainly does help."

Likewise, says psychologist Mindess, you don't have to be sick to need and appreciate humor. "Everyone conducts their lives to some extent in foolish ways. We pursue odd goals, we fall in love with people who are not in love with us, we don't see our loved ones as they really are -- that's all cause for comedy."

"If we took humor seriously," adds cartoonist Wilson, "we might get a few more laughs. People start out with a great sense of humor -- look at any kid laugh. They do it with their whole body, they fall down. So everyone's got it.

"Unfortunately, in the process of growing up, we get that confused with choking things down. But you can't throw away the knack of seeing how funny things are . . . We should all get the joke, because it's a wonderful joke."