Mark Ruffalo has said he thinks his new film Infinitely Polar Bear helps normalise mental illness.
The actor stars in the film written and directed by Maya Forbes, inspired by her own father, about a man with bipolar disorder who tries to win back his wife by taking full responsibility of their two daughters.
Speaking at the Toronto International Film Festival, Mark said of portraying a character with mental illness: " It's an important issue, it's a big issue, I say you either are one or you love one. and I feel like the movie really does normalise it, it takes a lot of the mystery out of it."
And he admitted it was a daunting prospect working with Maya on a project that was so close to her heart.
He said: "It's a big deal. I know how important your father was to you. We're dealing with some difficult issues of mental illness and raising kids in an unorthodox way and their family history. So yeah it was daunting, but the minute I met her and started talking about it I felt we were in deep collaboration."
Screenwriter Maya, who makes her directorial debut with the film, said Mark understood from the beginning what she wanted to portray in the film.
She said: "I wanted to show that a person's not defined by their mental illness, that's just a part of them.
"We were on the same page. We wanted it to be real but we wanted it to be funny and we wanted it to be sad. We wanted the whole range of life."
Mark, who is 46, has gradually achieved recognition for his acting since his mid 30s, and has recently gained global fame since starring in the Marvel movies as The Hulk.
Hearing that fans had been waiting for hours to see him on the red carpet at the festival, he confessed: " It's very humbling and it makes me feel bad that they've been waiting here since two o'clock. It's different, it's new to me and so I'm trying it on, I'm taking it for a spin."