This is one of those movies that I could not get out of my head for days. It was a great, realistic story of a drug-addicted teacher who balances his love and concern for his students with his addiction. It's an accurate portrayal of human nature, and it conveys the fact that just because a person does something wrong, it doesn't make them a bad person.
The movie was appropriately rated R. There were around 30 f-words, and numerous other profanities throughout. The drug content was detailed. We see a couple having sex, but nothing in detail, and it's shown in short clips, not the whole seen at once. Danny does almost rape his girlfriend, but it's nothing detailed, and nothing more than would be shown on some TV shows.
Overall, I think this is a good movie for adults. Definitely not for kids.