Think I understand the ending.... Spoiler

We are thrown off by George's girl friend. She's sitting by his bed and says, "It could happen to anyone." Then George hears the music that they play during meals at the asylum and what he is seeing is his friends alive but Max begins to cut up his hand. I think that not only was seeing his friends a "vision" but so was his seeing his girlfriend along with everything she said. Bottom line: George was catatonic by the end. Catatonic: Deep depression unresponsive to stimuli that may include "Seeing or hearing things that don't exist (hallucinations), especially voices." http://www.mayoclinic.com/health/catatonic-schizophrenia/DS00863/DSECTION=symptoms

George's girlfriend never said that, just as Max never cut up his hand.