She said: “Anything that you do that you obsess about and think about and give that much to for six months of your life in his case allows you to look deeper at yourself and the people around you and the effect of what you do and has to have some kind of therapeutic, cathartic end.
“I know that he is incredibly proud of the movie and I think that he is proud of what he's shown and I think he wants people to see that side of him and he's an incredibly private man so what he shows on screen is deep as you could possibly get.”
Jodie also insisted the troubled actor – who portrays depressed company chief Walter Black in ‘The Beaver’ – was the perfect star for the role, because he understands how it feels to want to “transform yourself”.
Speaking at the launch of the movie at the Cannes Film Festival, she added: “He was the right actor for the role and had a deep understanding of the struggles faced by the character. He really understood the character in a way that was extraordinary.
“I think that he was willing to go to such a deep place and willing to expose himself in some ways, to really talk about something he knows a lot about which is struggle, wanting to change, wanting to transform yourself, not wanting to be who you are and I'm so grateful for that performance.”