TIFF 2015: Brie Larson 'sad' over Room role

The 25-year-old actress plays a mother who has been held captive with her five-year-old son, and locked in a room, in Lenny Abrahamson’s big-screen adaptation of Emma Donoghue’s 2010 novel.

At the film’s premiere at the 2015 Toronto International Film Festival, Brie said: “I felt sad because it meant I had to let her go, and let her figure out her life on her own.

“When you become these characters, they kind of become your friends – you know them intimately, and every day they become a new discovery. To set that aside and move onto another phase of your life is always hard. But I was very happy to go to Hawaii, relax and let it go.”

Jacob Tremblay portrays her screen son Jack, with Joan Allen and William H Macy as Brie’s screen parents.

“I had a great time filming this movie. It was a pretty hard movie but it was also easy because this movie was mostly improvising,” he said.

“We (Brie and I) played Lego, we built toys together. I built a laser gun with her and we made a lot of stuff out of paper and pasta, so it was really fun to work with her.”

Brie revealed how she even spent a month indoors at home for a month to prepare herself for the shoot.

“I spent about six months ahead of time going on a very strict diet and gaining a bunch of muscle. I stayed at home for a month to see what that felt like,” she said.

“I worked really hard, but I always felt that no matter whatever it was that I did, nothing could compare to the real-life stories I have read. I read any story that I could and watched a lot of the news clippings as well. I was fascinated with how the media turned those stories.

“I have an incredible family, great friends that were always nearby so it never really got too dark for me.”

Author Emma said being at the film’s Toronto premiere was “a dream come true”.

“It is thrilling enough that a film has been made of my book at all, but this is a film I’m so proud of, and then to have it receive so much attention here at Toronto… I expect to wake up at any moment and find this is all a pathetic wishful dream,” she said.

She also revealed how her novel was inspired by her own experiences of motherhood, as well as real-life cases such as Austrian kidnapper Josef Fritzl, who was sentenced to life in 2009 for the enslavement of his daughter Elisabeth for over 30 years.

“My kids were four and one at the time so when I heard about one of these kidnapping cases, which happened to be the Fritzl case, I thought, ‘Oh my God. How could you be a good mother in a locked room?’” she explained.

“And then I thought this dreadful thought, which was motherhood sometimes does feel like a locked room. It’s got aspects that are claustrophobic as well as aspects that are beautiful and intimate, so it just struck as the perfect kind of metaphor of what it’s like to be a parent.”

Room will be released in UK cinemas on January 29, 2016.