Robert Downey Jr. thinks becoming a director would be good for his soul. The 'Sherlock Holmes' star - who has a history of drug addiction problems - still feels passionate about acting but believes he will tire for his profession eventually.

He said: "I will not be able to remain happy and sedate being an increasingly hireable actor type. I think the best thing I can do for my soul and my own development would be to direct.

"It's really easy for me to do landgrabs with my day job, and I still have a lot of passion for it - but if I had to guess, that would probably be my next move."

The actor admits he has often thought about a career change but never acted on it. He added to Britain's Esquire magazine: "I used to mention it every five years or so, between public humiliations. So it's been five years. It's time."