The torture of a teenage boy -- this is entertainment?

Rating: 5/10 (16 December 2019)

I didn't think this was a very good movie, but I was deeply moved by the performance of Alex Wolff as Peter, a young lost soul in a family torn by mental illness.
The movie draws you in in its first third, as we observe dour, washed-out mom Annie (Toni Collette) going through the motions of her life with Peter, odd daughter Charlie (Milly Shapiro), and calm, see-no-evil husband Steve (Gabriel Byrne).
Annie is deeply angry and bullies everyone in the family, fatefully forcing Peter to drag Charlie to a party one night. This demand makes no sense for anyone, but Peter goes along. Things go horribly, and Wolff is deeply affecting as a young person who tries to cope with trauma with absolutely no help from the adults in his life.
The rage that flares between Annie and Peter over dinner one night is stunning. However, the movie goes severely down hill from there, as it descends into a cheap knock-off of "Rosemary's Baby," with tacky references to "Poltergeist."
What I'm left with in reviewing this film is the anguished cries of Peter as he wrestles with his mother's insanity and cruelty. As the mother of boys who are about Peter's age, I found the poignancy of Peter's situation to be wrenching. What a bravura performance!
I've read that some other reviewers think Ms. Collette should have gotten an Oscar. She is indeed scary in this film, but to my mind, her antics are far from indelible.