Beautiful Boy director Felix Van Groeningen hopes the film can change the perception of addiction.
The drama starring Steve Carell as a desperate father trying to help his son, played by Oscar nominee Timothee Chalamet, who is addicted to crystal meth.
It is based on a true story and best-selling memoir of Nic Sheff and his father David.
Van Groeningen described the addiction as a "disease" and hoped the film could help the public's understanding of the subject.
He told the Press Association: "It's really a story about unconditional love. It's a very beautiful family and I really fell in love with this family, I wanted to tell this story, it's inspiring, because they went through that, they found a way to that.
"This movie is not saying there are easy answers when it comes to addiction because there is not, but it's an inspiring story.
"It's out there (the movie), people are talking about it and this is impacting people. That's why I wanted to make this film, it's an important and timely story that says, deep down, that addiction is not a choice, it's an illness, it can be treated. "
Belgian director Van Groeningen, who is making his English debut with Beautiful Boy, added: "It's amazing to see when we make projections and Q & As people get emotional and cry and start talking about their own experience and anything this helps this is incredible.
"I hope this keeps happening."
American actor Chalamet, 22, won recognition and applause for his parts in 2017 in films such as Hostiles and Call Me by Your Name, in which he was the leader.
Van Groeningen said his cast happened when "he was not the star he is now," but he impressed the filmmakers during the audition process.
And he praised the chemistry between Chalamet and his father on the screen, Carell.
He said, "There was this vibration of father and son, immediately. Steve hugged Timothee at the end of the scene and it was very exciting to see. That was just the beginning. "
Beautiful Boy is set to be released in UK cinemas on January 18th.– Press Association