The `Moneyball` star has revealed his marijuana smoking got out of control in the late 90s because he was trying to escape the pressures of fame.
He told The Hollywood Reporter magazine: "I got really sick of myself at the end of the 1990s. I was hiding out from the celebrity thing, I was smoking way too much dope, I was sitting on the couch and just turning into a doughnut and I really got irritated with myself."
The publication`s executive features editor Stephen Galloway revealed the actor credits his drug use to depression.
Galloway said: "He said it`s like he had a semester of depression.
"He hasn`t had that in this decade, but he definitely wrestled with it in the past."
Last year, the 48-year-old Hollywood star - who was nominated for the Best Actor Oscar this week - even quit smoking regularly cigarettes after being caught puffing by two of his children, daughters Zahara and Shiloh.
Brad and his long-term partner Angelina Jolie also raise four other kids together - Maddox, Pax, and twins Knox and Vivienne.