On Thursday, ABC News' Dan Harris re-watched footage of his on-air panic attack.

Harris, who co-hosts "Nightline" and is a correspondent for the weekend edition of "Good Morning America," revealed his past drug use last month, and said it was a panic attack he had on air that prompted him to seek help. He recently looked back at the episode for "ABC World News."

Appearing on HuffPost Live Thursday, he re-watched footage of what he said was a "meltdown." Harris had been reading the news on "Good Morning America" when he grew short of breath and cut the segment short.

"5.019 million people" watched the episode, he said. Harris told Huff Post Live's Marc Lamont Hill that "his full-on panic attack" was caused by his cocaine and ecstasy use, which started after he returned from war reporting and slipped into depression.