I See Monsters - PJO

Percy Jackson is not normal. He knows this, has known for a while. He knows that others don't see things like he does, they don't see the lurking monsters at every turn; beasts only a disturbed mind such as his own could conjure. He knows this. He's learning that the world is never kind to those that are different. But he's also learning that sometimes it's ok to rely on others. And in a world filled with savagery - real or not - nothing is normal.. And Percy is yet to face the worst.

OR...

Percy has schizophrenia and deals with mental struggles which he tries to overcome.