He tells Newsweek he started when he got to Hollywood in the '70s when so many were doing cocaine, it was part of movie budgets.
He says he got so addicted his life became "a mess."
He was sleeping only an hour a night.
It finally got to the point where he had what he called a "white-light experience," which made him realize he'd be dead in five years if he didn't quit.
He says he checked himself into rehab the next day.
