Robin Williams

This photo of actor Robin Williams and his wife Marsha, along with their daughter Zelda, was taken as they arrived at the premiere of the film "Patch Adams" in New York City on Dec. 13, 1998. (Jeff Christensen / Reuters / REUTERS / August 11, 2014)

Editor's note: This interview with Robin Williams by arts writer Frank Rizzo ran Dec. 20, 1998. Williams was found dead of an apparent suicide on Aug. 11, 2014.

Robin Williams was explaining the main theme of his new film, "Patch Adams," which opens nationally on Christmas. In the movie, he plays an outrageous, older-than-usual medical school student who believes that the power of laughter and caring can have very real health benefits.

 In the late '60s, the real-life Adams was depressed and suicidal. Committing himself to a mental institution in Virginia, he discovered he had a gift to help others. So he decided to go to medical school, where he was at odds with the establishment, which saw his antics to brighten patients' lives as being unprofessional. (The real Patch Adams eventually formed the Gesundheit Institute, dedicated to a more connected, personalized approach to medicine.)

 "There is such a thing as bedside manner," says Williams during a recent weekend of interviews promoting the film in Manhattan. "And some medical schools have gone back to teach that." Suddenly he turns from sensitive to silly. "I don't often touch in interviews, you know. Let's hug! Oh, daddy!"

Robin Williams reaches out and touches his interviewer gently on the hand.

 "Just this can be very reassuring," he says, gently caressing the palm.

Williams was explaining the main theme of his new film, "Patch Adams," which opens nationally on Christmas. In the movie, he plays an outrageous, older-than-usual medical school student who believes that the power of laughter and caring can have very real health benefits.

 In the late '60s, the real-life Adams was depressed and suicidal. Committing himself to a mental institution in Virginia, he discovered he had a gift to help others. So he decided to go to medical school, where he was at odds with the establishment, which saw his antics to brighten patients' lives as being unprofessional. (The real Patch Adams eventually formed the Gesundheit Institute, dedicated to a more connected, personalized approach to medicine.)

 "There is such a thing as bedside manner," says Williams during a recent weekend of interviews promoting the film in Manhattan. "And some medical schools have gone back to teach that." Suddenly he turns from sensitive to silly. "I don't often touch in interviews, you know. Let's hug! Oh, daddy!"

 It's hard not to laugh. And feel good.

 Williams has personally seen the power of laughter, of caring, of the human touch on patients, ranging from children from the Make a Wish Foundation, to his good friend Christopher Reeve, who was paralyzed in a horse-riding accident.

 "It's all about connections," he says.

 And science has proved him right, with research proving that laughter and caring increases endorphins -- naturally occurring painkilling substances in the human body -- which reduces the amount of medication patents require and speeds their rate of recovery.

 And the benefits are for the giver as well as the patient.

 "For me, laughter is cheaper than Prozac," Williams says, half seriously. when I see a patient or a child or Chris laugh, I get it back. It's it's symbiotic."

 But Williams is not so big a fool as to advocate laughter and caring as the only prescription for illness.

 "It's a very delicate thing to know when is the right time {to bring in the humor} to a patient," he says. "With Chris, there are certain things I can joke about, and other moments when I know it's not appropriate and just to be there for him."

 And like the best humor, timing is everything. He understands doctors can't always be silly or overly sensitive.

 "There has to be a certain professional quality to a doctor, a certain clinical distance," he says. "You can't have a heart surgeon in the middle of an operation go: `No! Arrrggghhhhh!! I can't cut it!!!'"

 But Williams himself has never been in such a state of depression where humor wasn't welcome, even for a cameo appearance.