The comedian was struggling with addictions to heroin and alcohol when he launched his career with his first big job as a presenter for MTV in the U.K.
The Forgetting Sarah Marshall star admits several of his celebrity interviews were conducted while he was under the influence of drugs, and his behaviour backstage wasn't very professional either.
He recalls, ""We used to nick (steal) stuff out of each other's dressing rooms because I was on drugs in the early days. We nicked all Fatboy Slim's stuff, all his booze.
""They said, 'Wait in there for Fatboy Slim,' and I was like, 'There's booze there - we'll have that!'""
Coincidentally, both Brand and Praise You hitmaker Fatboy Slim are now teetotal after conquering their drink demons.