Brad Pitt insists marriage is more than "just a title".

Brad - who was previously married to Jennifer Aniston - said: "I wouldn't say [marriage is] just a title. There's more to it than that."

The 'Moneyball' star - who has children Maddox, 13, Pax, 10, Zahara, nine, Shiloh, eight, and six-year-old twins Vivienne and Knox with Angelina - admitted he is "slowing down" his movie career in order to give himself time to do new things and spend time with his family.

He told the new issue of Britain's GQ magazine: "I've been slowing down for a while now. And slowly transitioning to other things. And, truthfully, I do want to spend more time with my kids before they're grown up and gone."

However, despite his apparent contentment with his personal life, Brad remained cryptic when asked if he is happy, branding life a "series of trade-offs".

Asked if he feels happy, he said: "I've always believed happiness is overrated, you know?

'It's those difficult times that inform the next wonderful time, and it's a series of trade-offs, of events, of wins and losses."

The 'Burn After Reading' star - who was raised in Springfield, Missouri - also joked he is a "miserable b*****d" compared with his friend George Clooney.

Following George's recent description of Brad as "unreachable", his pal replied: "Well, you know, George is extremely accessible. He's one of our best representatives. He's funny as s**t. He's a joy to be around. I guess maybe I'm more of a miserable b*****d.

"I'm a bit of a loner you know? I'm more quiet by nature. And coming from, you know, hillbilly country, I'm probably more reserved."