Schizophrenia is a serious and chronic medical condition. It is a disorder of the message system in the brain. Someone with schizophrenia loses the ability to act properly or to think clearly - their mind is "split from reality" (hence schizo "split" and phrenia "mind" from ancient Greek). The term schizophrenia does not refer to multiple personality disorder.
Schizophrenia affects about 1% of people throughout the world. It sometimes starts during childhood, but most often shows up in the late teens or 20s. While it affects men and women proportionately, the average age of onset is somewhat lower in men.
It can develop gradually, over the course of weeks or months, or it can seem to come on very suddenly. The signs of schizophrenia are easy to misunderstand, and can sometimes be frightening to other people. While this disorder never goes away, it can often be managed with proper medical care and family support.