Robbie Williams was "dying" three years ago.
The 'Bodies' singer admits his spiral into addiction had got so bad that he was close to death in 2007 - and didn't care about it.
He said: "I was not in a good place. I was dying. I got to a point where I really, genuinely didn't care.
"I'd just got fat and depressed before. Then this one was like, you might die, now. Cool!"
Robbie, 36, claims his addiction to drugs began in 1993, when he first took cocaine given to him by an unnamed 80s pop star.
He said: "I'd already tried speed, ecstasy and acid but never cocaine. I think it was a symptom of a problem personally for me, for my own make-up. And also professionally for me where I was, with the people that I was with
and how we were being looked after."
However since a trip to rehab in 2007 Robbie - who is engaged to actress Ayda Field - has been getting his life back on track, although he admits he did pile on the pounds last year because his overuse of the drug cannabis, known as weed, made him constantly hungry.
He told Radio Times magazine: "Did you see me last year? Have a look at last year. Year of the munchie, 2009. Weed, it's such a lovely drug. But it doesn't mix well with me - at all. It doesn't take much to trigger- I mean, I'll get psychosis from a cup of tea! Seriously. The caffeine in that is enough!"