Among a number of very good lines in “Ezra,” a film about the challenge of raising an autistic child, there’s one that really encapsulates the problems parents and caretakers can face.

Bobby Cannavale plays Max Bernal, a struggling comedian with his own behavioral issues who feels his best efforts to connect with his son, Ezra (William A. Fitzgerald), are failing, leaving him desperate and increasingly angry.

“The word autism comes from the Greek: ‘In your own world,’” Max says to a friend, Nick, played by Rainn Wilson. “I don’t want Ezra in his own world. I want him in this world.”

“Ezra,” which opened recently at Amherst Cinema, is — to invoke an overused term — a heartfelt story that gets the main things right, offering a nuanced, honest portrait of a family strained to the breaking point by the effort to help Ezra find his place in that real world.

And if the film, directed by Tony Goldwyn and written by Tony Spiridakis, lapses into occasional Hollywood contrivances and clichés, it’s buoyed by some excellent performances, especially by Cannavale and Fitzgerald, a first-time actor who’s 15 and is on the autism spectrum himself. (The movie also featured a producer and a number of other crew members who are neurodivergent.)

In fact, Spiridakis wrote the script based on his own experience raising an autistic son, which eventually contributed to the breakup of his marriage, and the story feels real, while offering some good comic moments.

“Ezra” begins from a somewhat similar standpoint. Max, a former comic writer who’s now trying to make it as a stand-up comedian in the New York City area — part of the movie is set in Hoboken, New Jersey — and his ex-wife, Jenna (Rose Byrne), are butting heads over what to do about 11-year-old Ezra, who lives with Jenna and her lawyer boyfriend, Bruce (played by Goldwyn).

Ezra’s a bright kid — he reads the New York Times — but he’s often on his own toothy wavelength. A lot of his speech consists of lines plucked from movies, TV shows (“Breaking Bad” is a favorite), and other pop culture sources, he struggles to look people in the eye, and he refuses to allow himself to be hugged.

Max, meantime, is living with his father, Stan (Robert DeNiro), a crusty former cook now working as a doorman at a fancy apartment building. They aren’t exactly great together; you sense a lot of unspoken and unresolved emotional history between them, and it’s revealed that Max’s mother walked out on the family when he was a kid.

Max is a bit of a hothead who appears to have burned a few bridges in the past. There’s a funny reference made at one point by his manager, Jane (Whoopi Goldberg), about Max once having punched Conan O’Brien in his family jewels. “I didn’t know he was so tall,” Max responds.

Now, with things not exactly going great in his career, Max is really pissed when the principal and a social worker at Max’s school say his son is increasingly disruptive and should be placed in a special needs school.

Jenna is inclined to follow the advice of the specialists, including that of a doctor who wants to put Ezra on a trial run of Risperdal, an anti-psychotic drug. But Max is having none of it. He doesn’t want Ezra taken away from “normal” kids, and he accuses the doctor of pedaling drugs.

“Oh, now I see where the dangerous behavior comes from,” the doctor says archly, and Max lunges at him, which briefly lands him in jail.

Yet you can sympathize with Max: It’s heartbreaking to see his grief when his son won’t let him hug him, and when he’s forbidden to see Ezra for a month after his tussle with the doctor. Neither Max nor anyone else in the family is a villain. Everyone is exhausted by worry, frazzled and frustrated, and nobody knows what to do, with Ezra pulled in different directions himself.

At the center of Max’s anger is his feeling of powerlessness, his inability to oppose what he sees as a bureaucratic system built on the kind of “interventions” that can involve drugs and/or isolating the children from the mainstream, and which may overrule the wishes of parents.

Max is convinced he must do things his own way. Offered a chance to appear on The Jimmy Kimmel Show, Max kidnaps Ezra from Jenna’s apartment, commandeers Stan’s aircraft-carrier-length Cadillac, and sets off for Los Angeles, hopeful of getting his big break and freeing his son from his new school and drug regime.

This impulsive move sets loose all manner of chaos. A nationwide law enforcement alert is issued for father and son, Jenna and Stan take off in pursuit of them, and Max and Ezra will face their own crisis, including one confrontation that leads Ezra to try and run away.

After Max tells his son that he needs him with him to make his stand-up comedy work, like a real-life lucky charm, Max yells “I’m not your mojo, I’m not your superpower — I’m your son! And I want to go home!”

Without giving the details away, Max and Ezra have other encounters on their road trip to L.A. that are moving and funny even as they sometimes strain credibility or veer toward triteness.

But “Ezra” always gets back on track through the strength of the acting, particularly by Cannavale, who’s convincing both as a tart-tongued comic and as a father who, despite all his faults, is trying to do what he thinks is right for his son, and what will bring them closer.

“This kid,” he says to a childhood friend he briefly reunites with on the cross-country trip, “is the one thing I can’t get wrong.”

Cannavale and Byrne — she’s very solid as the mother who deeply loves her son and wants him back — are partners in real life, with two sons of their own, and their scenes with Fitzgerald seem natural and unforced.

And DeNiro, taking on a role he’s played so often — New York working class guy of relatively few words — also shines as a man who’s held much inside through his life but who finally reaches out to Max.

Reviews of “Ezra” have generally been good, with some mixed thoughts on how well it tackles the complex issue of autism. But critics seem to agree that the film’s heart and good intentions are very much in the right place, and I’d agree. If the film grades out to a B+ overall, it gets an A for effort.

“Ezra” is playing at Amherst Cinema through at least June 20. Visit amherstcinema.org for show times.

Steve Pfarrer can be reached at spfarrer@gazettenet.com.