Ledger says playing 'The Joker' left him mentally drained

Heath Ledger has been left physically and mentally drained by his latest role as 'The Joker' in the new 'Batman' movie.

Ledger has found his latest role as a mass-murdering psychopath difficult, with the part leaving him so disturbed he is finding it almost impossible to sleep.

He says: "It is a physically and mentally draining role. He's this psychopathic, mass-murdering, schizophrenic clown. It takes a lot of preparation to play.

"Last week, I probably slept two hours a night. My body was exhausted."