Preview: Weeks before his death, Bob Saget reflected on how laughter "truly helped me survive"

In one of his final interviews, Bob Saget speaks with Dr. Jon LaPook about using humor in dark times

Weeks before his death, Bob Saget opened up to CBS News about how laughter helped him through the best and worst of times.

In an in-depth interview airing Friday, Saget spoke to CBS News chief medical correspondent Dr. Jon LaPook, who was a good friend. He reflected on making people laugh when he was just 4 years old.

"I would dance in the living room and just start dancing, dancing stupid to make anybody laugh - just like silent film stars," Saget said. "And I knew some jokes, but it wasn't really jokes. It was just like; I've got to perform. I've got to make people laugh."

Saget said humor was a defense mechanism.

"It truly helped me survive and it helped keep me mentally alive, rather than letting it destroy me," he added.

He also spoke to LaPook about his mission to raise awareness of scleroderma, the disease that took the life of Saget's sister. Saget helped raise more than $26 million for the Scleroderma Research Foundation, with the help of his entertainment friends.

The interview took place in December, weeks before Saget was found unresponsive in his Orlando, Florida, hotel room. He was pronounced dead at the scene. A cause of death is unknown at this time, pending the results of an autopsy report.

More of Dr. LaPook's interview with Bob Saget will air on "CBS Mornings" on Friday, January 14.