SIR Anthony Hopkins has to take care when he plays intense characters on the big screen because he has come to realise he suffers minor breakdowns with every role. The Welsh-born Oscar-winner admits he suffers from depression when he plays characters like former US President RICHARD NIXON and mentally unstable genius ROBERT in new movie PROOF.

He says, "I've never been aware of it in the past but I guess it does affect me. I remember when I played Nixon I had a sort of minor crack-up - depression and all that sort of thing.

"And, with this last part, I did feel unwell. I just felt depressed... I don't think I'm crazy, but I think if you're on set every day dressed like that and speaking those lines, as I was, I think it does get into your nervous system because the body doesn't know what's happening."

And Hopkins reveals he was so concerned about his penchant for letting characters get into his psyche, he insisted on performing a heart attack scene in 1998 Meet Joe Black twice - and no more.

He explains, "I was working with a director who loved to do a lot of takes... I had to have a heart attack, so I said to myself, 'Get a doctor to check out what it's like to experience a heart attack.'

"I said (to director Martin Brest), 'I'll give you two takes that's all... because my body doesn't know I'm not having a heart attack."