Neal Shusterman's novel Challenger Deep is a National Book Award winner for 2015, and it's not hard to see why.
Caden lives in two different worlds. One is a world you probably recognize, which involves school, home, family, and what we would call the real world. In the other, he's on a ship headed for Challenger Deep, the deepest point on Earth, with a lot of people and events we would find unusual. These worlds are starting to collide more frequently and with bigger consequences, and in the first world, he is diagnosed and treated for schizophrenia.