If she suffers schizophrenia, probably the scene in which she breaks the mirror and attacks Lily isnt truth; therefore she couldnt have stabbed herself. I also find it hard to believe the fact that she danced with a big blood spot the whole presentation and no one in the crew or crowd notice and she never fainted while dancing because of the loss of blood. I dont believe the ending is real. I think the ending is symbolic and Nina dying as the white swan is actually Nina accepting that the world is not that good and shes losing her innocence. Another thing can be that she lost her rational side and became totally insane. About the film, I believe some of the scenes were not necessary; they could have been less explicit. It was a great film and I loved the theme.