The Chumscrubber (2005)

The Chumscrubber starts out with Troy, a normal teenager who supplies "feel good" pills to everyone in his high school (this way he spreads happiness all around). But when his friend Dean pays him a visit, Dean discovers Troy has hanged himself in his bedroom during one of his mother's pool parties. After the death, three local teens: Billy, Lee, and Crystal, want what's left of Troy's stash of pills and they know that Dean is the only one who knows where they are. But when Dean refuses to get the pills, the three teens kidnap Dean's little brother, until they realize they've kidnapped the wrong kid.