Keira Knightley needs to have a "really nice time" after filming dark roles.
Yes, I was different then to the way I am now because you change with your experiences.
The 'Dangerous Method' actress doesn't find acting particularly theraputic, and admits she needs to properly relax at the end of a day's work in order to stop her roles making her upset.
She said: "A lot of people say that acting is like therapy, but I don't go for that.
"It's not my cup of tea, it is for some people, but not me. I do, however, find it incredibly cathartic and when you're playing something so dark you want to have a really nice time afterwards, otherwise it's far too depressing."
The 26-year-old actress - who is in a relationship with Klaxons rocker James Righton - also admitted that her fame has changed her, but she thinks it would be "sad" if she remained the person she was at the beginning of her career.
She added in an interview with the Daily Telegraph newspaper: "Yes, I was different then to the way I am now because you change with your experiences. It would be sad if you didn't, but my level of fame is not as big as Brad Pitt's thankfully."