Contrary to popular belief, schizophrenia is not the same thing as dissociative identity disorder/multiple personality disorder. (Which is I believe what you were suggesting with that joke.)
From Wikipedia:
Schizophrenia is a mental disorder characterized by a disintegration of the
process of thinking and of emotional responsiveness. It most commonly
manifests as auditory hallucinations, paranoid or bizarre delusions,
or disorganized speech and thinking, and it is accompanied by significant
social or occupational dysfunction.
http://en.wikipedia.org/wiki/Schizophrenia
http://en.wikipedia.org/wiki/Multiple_Personality_Disorder