I’m not a fan of dysfunctional-families-back-together-for-the-holidays movies like “August: Osage County,” “Home For The Holidays,” or “The Family Stone.” So, I admit I had a little bias against “Ben Is Back” before it even started. Fortunately, the plot’s a little different this time.

Ben (Lucas Hedges) shows up unannounced at his parents’ house on Christmas eve, fresh from his latest rehab stint. His mother Holly (Julia Roberts) is surprised but happy to have her boy home, but his stepfather Neal (Courtney B. Vance) is wary, because Ben has pulled stunts like this before, and it hasn’t gone well. The question throughout the movie is whether Ben has really stopped using drugs, and how much Holly can trust him. Meanwhile, he’s rolling around on the floor with his two youngest siblings, having a great time.

Despite Holly’s efforts to keep Ben close to her and clean at all times, things get ugly. I won’t give away what makes the situation turn, but let’s just say that it’s a very small town and some of the people whose paths Ben crossed before are not thrilled he’s back. Thus begins a bit of a dramatic roller-coaster for the second half of “Ben Is Back” that’s not entirely believable.

For that, you can blame Lucas Hedges’ father, Peter, who wrote and directed the movie. He’s trying to say something important about families that get caught up in the opioid crisis, but his plot line goes astray (as does Ben) and lapses into predictability as it plays out over a 24-hour period.

Roberts, meanwhile, is as good as ever playing Holly as a mother who desperately wants her son to be sober and straight, yet is wary of being too trusting. Her trademark smile is present at times, but she also plays the heartbreak very well. It’s too bad the rest of the movie isn’t as good as she is. As for the others, Hedges is fine as Ben, Vance isn’t given enough to do as Neal other than scowl, and the bad guys seem like they were hired from Typecast Central.

All in all, “Ben Is Back” is a nice effort that doesn’t quite work. I give it a 5 out of 10.