"If you talk to God, you are praying; If God talks to you, you have schizophrenia. If the dead talk to you, you are a spiritualist; If you talk to the dead, you are a schizophrenic." - Thomas Szasz

Mostly a matter of who's making the definitions, really. As Szasz's literary descendant once said:

"There's no such thing as crazy, just behavior that society has deemed unacceptable."