Robert Downey Jr. is amazed at how "fantastic" married life is.

The 'Iron Man 2' star - who married the movie's producer Susan Levin in 2005 - credits his spouse for helping him turn his back on drug addiction and can't imagine ever living without her.

He said: "I don't joke when I say she is my better half. She truly is.

"I cannot believe what a fantastic life I have today. But here's the thing, she didn't change me at all. She just gave me an ultimatum at a certain point.

"Ultimately, we both changed a lot so that now I can't ever imagine a life before her. I've certainly come to believe that Mrs. Downey and I together are definitely better than me alone or me and anybody else."

The actor also believes his role as Tony Stark in 2008's 'Iron Man' finally helped him turn around his image, and hails his transformation as a miracle.

He added to The Independent newspaper: "It's pretty miraculous. Although I'm not sure the public's opinion of me changed, it was more of a movie industry thing.

"Nonetheless, it's mind-blowing to me because I always felt like I could do something like this, even when nobody else agreed. It's wild."