In Black Swan, my impression was that Nina's psychosis occurred in part due to both the pressure she put on herself to be "perfect," as well as the creepy relationship and emotional manipulation with her mother (e.g. licking the icing off of her mother's finger, her mother saying she'll dump the birthday cake in the garbage because Nina doesn't want to eat it, saying that having Nina was a mistake that ruined her own ballet career, controlling Nina by constantly calling her to keep track of her, etc.).
I was pretty convinced that all of this emotional manipulation was real since it doesn't contradict anything else seen in the movie. However, I was recently talking to someone who argued that Nina's perceptions of her mother were probably distorted by her mental illness. Is there any consensus or official position on this?