Charlie Bartlett (2007)

Although cheerful, friendly, well-dressed, and authentic, Charlie Bartlett has problems: his father is gone, his mother is loopy and clueless, he's been expelled from private schools for victimless crimes, he's getting punched out daily at his new school, the local public high - and, he longs to be popular.
He makes peace with his tormentor by going into business with him: listening to kids' problems and selling them prescription drugs. Charlie's attracted to Susan, the daughter of the school's laissez-faire principal. New security cameras on campus, a student's overdose, and Charlie's open world view get him in serious trouble. Can the physician heal himself and just be a kid?