ADAM ROUNTREE / Invision/AP 1 / 5
ADAM ROUNTREE / Invision/AP 1 / 5

In a recent televised discussion about his life-saving heart surgery, late-night talk show host David Letterman confessed he takes medication to battle depression.

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The TV personality joined comic Robin Williams and former President Bill Clinton to talk about his second chance at life as part of a Barbara Walters news special, which aired on Friday.

The "Late Show " host underwent emergency heart surgery in 2000 and chatted candidly with Walters about his feelings of joy following the operation.

But they didn't last long.

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During the segment, Letterman stated, "Depression is a black hole ... I've dabbled in it.

"There's a difference in being sad and being blue and being depressed and being chemically or clinically depressed. I do know the difference between those and it's horrifying.

"Without some kind of medicinal help ... institutions used to be full of people who were depressed."

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Asked if he was on meds himself, Letterman said, "Yes, I'm on medicinal help."