I think everyone gets poor treatment from somebody at sometime or another, with or without the mental health issue but when we have mental health issues, we often take it more personally and to heart.

For example, the "full moon" ER comment is common and, for doctors, covers accidents and violent crimes, fights in bars and drug overdoses, which literally seem to increase when the moon is full. I don't think anyone is equating people with mental illness with werewolves?