This is the 2007 version. Click here for the 2017 chapter 12 table of contents.


Psychoses are major psychological disorders in which a person experiences a breakdown of normal reality-orientation. In other words, the person seems to be living in another world and may have trouble with routine tasks such as getting dressed or holding a job. DSM-IV lists many types of psychotic disorders, but the most common by far are the varieties of schizophrenia. Schizophrenics account for over 50% of the admissions to psychiatric wards and mental hospitals in the United States.

What is a psychosis? What is the most common type?

The onset of schizophrenia often occurs early in life, thus the old label for the syndrome-dementia praecox—literally "the dementia of youth." However, that label is not used any more, because the disorder is not limited to young people. Older people and children can develop schizophrenia, too.

What are typical symptoms of schizophrenia?

Schizophrenics suffer disturbances of thought or speech, blunted or inappropriate emotions, hallucinations (perception of things which are not there), and delusions (persistently held, false beliefs).

To what does the prefix "schizo" (split) refer?

The prefix schizo means split, but schizophrenia is not the same thing as "split personality." Mental health professionals were disappointed when a movie by comedian Jim Carrey re-introduced the error in 2000, referring to Carrey's character, who had a multiple personality, as "schizophrenic." Schizophrenia has nothing to do with multiple personality, and sufferers of Dissociative Identity Disorder (multiple personality) are seldom schizophrenic. The name schizophrenia comes from the gap that develops between a schizophrenic and reality. A schizophrenic may laugh at nothing, hear voices, or develop strange delusional systems, giving the impression of being split off from normal reality.

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