‘Beautiful Boy’: Timothée Chalamet and Steve Carell are superb in a moving portrait of addiction and familial love

After the credits finished rolling for “Beautiful Boy,” a moving portrait of familial love in the face of addiction, the Toronto International Film Festival audience at the Elgin Theater predictably went nuts when Timothée Chalamet came on stage. Steve Carell, who plays Chalamet’s father in the film, received warm applause too.

But the biggest ovation came when the real-life subjects of the movie, David and Nic Sheff, arrived. “Beautiful Boy” is their story, based on their own bestselling memoirs, and Chalamet still seemed skittish in their presence.

“We had dinner last night and it was, like, all of us, and I’m a firm believer that the art takes place in the head of the audience member and yet there was a tremendous anxiety in what Nic and David were going to think about this,” Chalamet said during a Q&A following the film. “I hope you guys aren’t lying when you say you like it.”

“Beautiful Boy” chronicles Nic’s descent into crystal-meth addiction and David’s attempts to understand and accept what has happened to his son and help save him. The film, directed by Felix Van Groeningen (“The Broken Circle Breakdown”), doesn’t sugarcoat or sensationalize addiction. As much as David wants his son back, he’s powerless to break the cycle.

“So often we have this image of what drug addiction looks like,” David Sheff said, “and it’s not fun. Our loved ones who go down that path are in pain.”

Added Nic: “I’m just so incredibly grateful … what a miracle that my dad and I are sitting together here.”

The movie can, at times, feel a bit repetitive in its singular focus on relapses and recovery, and there are moments when you might wish Van Groeningen had abstained from some on-the-nose song cues. (Your reaction to Perry Como singing “Sunrise, Sunset” might define how you feel about the movie.)

But “Beautiful Boy” is worthwhile for the acting of Carell and Chalamet, both of whom could earn Oscar nominations for their work here. (While category placement hasn’t been firmly set, it looks like Carell will be placed in lead, with Chalamet supporting, which would accurately reflect their screen time in the movie.)

Chalamet was cast here before his 2017 Oscar nomination for “Call Me by Your Name.” Carell called his audition the “best in history.” You can certainly see that in the performance, which digs deep into the ways that drugs can drain and disconnect an addict from those who love him.

There’s a particularly brutal scene between David and his strung-out son at a diner that once held happier memories. Those memories haunt David, and Carell’s performance is a reminder that, over the years, he has become an actor expert in using silence.

It doesn’t help that David has two young children with his second wife (played beautifully by Maura Tierney). He looks at them and he remembers the beautiful boy Nic once was.

“I’d go home at the end of the day and just recount to [wife] Nancy what we filmed and she’d just be devastated,” Carell told me at a party for the film held at the Soho House. “It definitely was a thing where I’d go home and hug my kids as close as I could.”

The scene at the Soho House was extra intense, owing to Chalamet’s presence (and his new haircut) as well as a pop-in from his “Call Me by Your Name” co-star Armie Hammer. Producer Jeremy Kleiner said “Beautiful Boy” was 10 years in the making, which would put Chalamet at 12 when it was launched.

Based on the reception, the delays were serendipitous.

FULL COVERAGE: 2018 Toronto International Film Festival »

glenn.whipp@latimes.com