James McAvoy has said he wanted to be "sensitive" in his portrayal of a man with 23 different personalities in his latest film Split.
The Scottish actor plays a sufferer of dissociative identity disorder who kidnaps three high school girls in the psychological thriller from director M Night Shyamalan.
At a special screening at AFI Fest in Los Angeles, James said he tried to be "conscientious" in playing a character with a mental health disorder.
He told the Press Association: "You've got to be sensitive in your portrayal of people at all times. You've got to be conscientious and you've got to be aware of people's faults.
"You've got to be aware of people's good points and their graces. I think that's the case all the time when you're portraying somebody who's suffering or whose way of life is very different from your own."
James plays Kevin, whose different personalities include a nine-year-old boy called Hedwig, a woman called Patricia and Barry, who he described as a "straight guy trying to gay".
James 37, said he had been told he was a "pain in the bum" off-screen when playing certain characters but he was unsure if his latest role affected him away from the camera.
"I'm not really aware of how things affect me off-screen," he said. "Afterwards some people tell me, 'you were a pain in the bum to live with or to work with you during that moment'.
"Generally when I'm going through it I'm not aware of it and I'm trying not to be too self aware of when I'm going through things. I try to be self possessed but not self aware."
Split is due to be released in UK cinemas on January 20