One Flew Over

Take a look at One Flew Over the Cuckoo's Nest by Ken Kesey.  It centers on a group of mental ward patients- their interactions and struggles.  Seen through the eyes of Chief Bromden, a taciturn half-Indian patient, Kesey's novel is essentially about the battle between good and evil, the fight between sanity and insanity.  If you're into books like A Clockwork Orange or Slaughter-House Five, you should definitely check this one out. amazon