Harry Potter: Fear is how I Fall (on going)

The central idea is that Hogwarts is a mental institution and that "every major event in the books is a fantasy/delusional version of the experiences that a child would encounter in the course of being institutionalized and forcibly treated for mental illness." The real world is the world with the Dursely's and the wizarding world is simply part of Harry's imagination. His violent encounters with Dudley are what got Harry sent to the mental instition/Hogwarts rather than his magical talents.