The film Beautiful Boy, starring Steve Carell and Timothée Chalamet, is in cinemas on 18 January.

It is based on the real-life story of David Sheff and his son Nic, who both wrote their own books about Nic's drug addiction.

David joined us on The Last Word to discuss the film and tell their story.

He feels Steve Carell's performance "captures the emotion of the time I went through, of not knowing whether my son was going to survive."

David wrote his book, Beautiful Boy: A Father's Journey Through His Son's Addiction, as a way of coping with what was going on. He hadn't originally intended to publish it, but later decided to do so when the situation had improved.

"It felt like there was a really valuable story in our experience. I wanted other parents to know that if they were going through this, they weren't alone."

Nic's parents divorced when he was very young, and David believes Nic felt caught in the middle and that the experience partly contributed to his problems with drugs.

He says reading Nic's own book gave him a different perspective on addiction: "When I read his book I realised he was not having fun, he was in pain. Addiction is not a choice, it's a disease."

Nic is now 36 and has been sober for nine years. He has devoted part of his life to trying to educate and support young people who are using drugs.

David says their relationship is "closer than ever."

To catch the full chat press the play button on the image on the top of the screen