Brad Pitt quit smoking cannabis because he became "disgusted" with habit.

The 48-year-old actor has made no secret of the fact he was heavily using marijuana in the late 90s as he tried to come to terms with his huge fame.

Brad - who starred in several hit films during the decade, including 'Interview with the Vampire, 'Seven' and '12 Monkeys' - has now admitted his drug use began to have a negative effect on his work and he stopped for the sake of his career.

In an interview with The Guardian newspaper, he said: "I was smoking myself into a doughnut, a mollusc. I got disgusted with it.

"At the end I came to the very simple conclusion that I wanted to make things and be part of stories that were personal and that I could bring value to and if I got this opportunity, to bring something of value to the zeitgeist of film making."

Brad - who raises six children, Maddox, 10, Pax, eight, Zahara, seven, Shiloh, five, and twins Knox and Vivienne, three, with his partner Angelina Jolie - also revealed the herbal high made him reclusive and affected his personality.

He explained: "I'd smoked a lot of weed. I was professional at it. I wasn't participating in life."

Brad was recently nominated for the Best Actor Oscar for his portrayal of baseball manager Billy Bean in the critically acclaimed 'Moneyball'.