Schizophreniacs are normal people with a severe mental disorder. They cannot help having it and did not ask to get it. They can be of any age, race, or gender. They are generally not violent nor do they have a problem with being bipolar. They are usually not split personalities either. They are just common people with a mental defect.
Heredity, biology, and perhaps body chemistry and immune disorders are thought to be causes for the mental illness yet no one knows for sure. One thing is for sure is that people don't do anything intentional to cause it. They never asked for it. They should be treated with respect and dignity and should be professionally helped.