Diary of a Teenage Girl (2015)

As my youngest son said, there is so much wrong with everyone in this movie, and if you wanted to look at how family's affect themselves, this is a gritty look at that.
Minnie is fifteen, it is the mid-1970's in San Francisco and her mother is drugging and drinking and openly sexual with her boyfriend in front of her teenage daughter.
This has exactly the outcome you would expect.  The daughter has been raised by a mother who craves attention, but cannot shower it upon her own children.  They grow up thinking the way people show they love you is by having sex with you.  You get the picture.
There are many cringe-worthy scenes, a few that are terrifying, both as a former teenage  girl, a parent, and a grandparent.  There are so many elements of human behavior that are on display here, all of them ring true, and it is beautifully acted.