I watched this movie with my 13-year old last night, and I'm glad she's already had good sex/drug education at school and that we could talk about it afterwards. I'm concerned that, although the average age parents have selected for this movie is 13, there will be many parents, like me, who would prefer not to have their child see this movie at that age. FWIW, my daughter had read the book earlier in the day and liked it better than the movie.
The movie, set in the early 90s I believe, depicts a high school freshman who inexplicably is taken up by a group of "misfit" seniors. I'm perhaps showing my age, but when I went to high school in the late 70s, the misfit kids didn't necessarily have parties at houses with no parents present, lots of alcohol, pot, and LSD, and lots of sex. I would have found the story more believable if it was set during the kids' college years.
Visual images of concern were some graphic depictions of characters in full costume at the Rocky Horror Picture Show...no one was nude in these scenes, but some were close, and there was a lot of the lascivious touching that was a big part of the movie. I was at least relieved that there was no depiction of the glorified incest from Rocky Horror, especially since the main character in the movie is eventually revealed to be the victim of childhood molestation by his aunt. Mind you, I'm not against Rocky Horror, but not for young teens. Another concern visually for me was the general attractiveness of this group of misfit teenagers who all appeared to be rich, have great teeth and skin, and who showed none of the effects one might expect of heavy alcohol use or frequent drug use.
Verbal concerns were Emma Watson's (skinny) character saying she is "bulimist" (not a bulimic but she loves bulimia) and a great deal of swearing which some parents may object to.
On the plus side, there is a sympathetic and compelling young gay man in the movie, and his friends stick up for him when he is bullied; however, his boyfriend is understood to be closeted and to need alcohol in order to loosen up enough for sex. The major message of the movie, that we get the love we think we deserve is one worth exploring with your teenager (in the movie this is applied to two females who are in relationships with physically violent men, a female character whose boyfriends always seem to end up as cheaters or creeps, the gay fellow whose boyfriend bullies him in the end). The main character does encourage his friends and sister to believe they deserve better. Another plus is that the movie does treat the boy's depression/anxiety/treatment by psychiatric professionals sympathetically. There is also a warm and caring (and appropriate) relationship between the boy and his English teacher.