Unrealistic
First of all, how does he have the time to do sessions with ALL those kids. Doesn't he ever have to go to class? At some points, there are 20-25 kids lined up outside the bathroom.
I like this movie, but 90% of it could never actually happen.
I don't care how many doctors he went to, he would NEVER be able to get all those prescriptions. It's hard enough to get things like xanax and ritalin from a doctor as it is, but to get it from multiple sources. He would have to be going to 25 doctors to be able to dole out prescriptions the way he does.
And the student lounge is unrealistic too. No high school would have that, especially without cameras.
Any others you can think of?