Brad Pitt says drugs turned him into a "doughnut".

The 'Inglourious Basterds' actor realised he had to move out of Hollywood when his marijuana use began to get heavier and he started isolating himself away from his friends.

He admitted to Parade magazine: "I liked to smoke a bit of grass at the time, and I became very sheltered. Then I got bored. I was turning into a damn doughnut, really. So I moved as far away from that as I could. I was done.

"In Missouri, where I come from, we don't talk about what we do, we just do it. If we talk about it, it's seen as bragging."

Brad, 45, has been dating his "soul mate" Angelina Jolie - with whom he raises six children - since 2005 but insists they have no plans to marry, despite being bombarded with hate mail over their lifestyle.

He explained: "I have love in my life, a soul mate - absolutely. When someone asked me why Angelina and I don't get married, I replied, 'Maybe we'll get married when it's legal for everyone else.' I stand by that, although I took a lot of flak for saying it - hate mail from religious groups. I believe everyone should have the same rights. They say gay marriage ruins families and hurts kids. Well, I've had the privilege of seeing my gay friends being parents and watching their kids grow up in a loving environment.

"I resent people telling others how to live! Just the other night, I heard this TV reverend say that Angelina and I were setting a bad example because we were living out of wedlock, and people should not be duped by us! It made me laugh. What damn right does anyone have to tell someone else how to live if they're not hurting anyone? How many times do you think real love comes to someone in a lifetime? If you're lucky, maybe two or three."

Despite their hectic family life, Brad and Angelina manage to enjoy private time together by sneaking off to a secret stone grotto behind a waterfall in his pool.

He joked: "It's a great place for sex."