After exploring drug addiction, depression and suicide in his previous films, Irish director Lenny Abrahamson found his most "uplifting" movie in Room, a harrowing tale of a young woman held hostage for seven years in her neighbour's garden shed.

The film won the People's Choice Award at the Toronto International Film Festival, and won similar awards at Aspen, Heartland and Vancouver film festivals.

Mr Abrahamson, known for independent films such as Frank, Garage and Adam & Paul, told Reuters that Room, based on Emma Donoghue's novel of the same name about a kidnapped young woman and her young son born in captivity, was a "journey from darkness into light".

A24's Room, out in US theatres on Friday (Oct 16), explores the intense relationship between Ma (Brie Larson) and five-year-old Jack (Jacob Tremblay) as they co-exist in the movie.

Jack, who was born in Room, knows nothing outside of it until he slowly learns of the world beyond the four walls that contain him through storybooks that their captor brings him.

Critics have received the film well, singling out young star Tremblay, who was aged seven during filming and had to perform raw emotional scenes with Larson.

Room goes on release in the US on Oct 16.