I think this movie should be required watching for all parents and their kids. It would never be able to be part of a high school curriculum due to it's "R" rating. There are disturbing scenes, but they are meant to be there. They tell the story. The movie tells the tale of four individuals and their fall into addiction and how it affects their lives. Some fall without even realizing it and that was scary! This is a movie that will stay with you and this is good for that means the message was received loud and clear!
There are many good links and reviews; take the time to read the link I provide here as it does a very good complete review.