Leonardo Dicaprio uses his friends as cheap therapy.

The Hollywood star - who plays US Marshal Teddy Daniels in his new movie 'Shutter Island' - admitted he has to turn to his pals and act like a "complete idiot" every now and then in order to escape the complexity of the characters he plays.

He said: "I go out and have a drink every once in a while. Ooh I know that's controversial, isn't it? I sometimes go on a vacation, too.

"I take what I do very seriously, and when I'm on the set that's all I focus on, so my vice is to hang out with my friends and talk about absolutely nothing of importance whatsoever and act like a complete idiot because I've got to filter out a lot of the serious stuff I'm dealing with all the time.

"It's like therapy to be a complete idiot with my friends, and it's just fantastic."

The actor revealed that playing Teddy - who arrives on a remote island to investigate the disappearance of a murderer from a hospital for the criminally insane - was the "deepest" he'd gone with a character and says he is now searching for some lighter roles.

He said: "This year is going to be the year of really taking care of myself because I've reached 35 and I've taken a lot of things seriously, maybe too seriously at times, so I'm going to make sure that whatever I do next and whatever choices I make are really right for me. And we'll see where that takes me."