disorganized schizophrenia
in DSM–IV–TR, a subtype of schizophrenia characterized primarily by random and fragmented speech and behavior and by flat or inappropriate affect, frequently associated with grimaces, odd or unusual mannerisms, laughter, and extreme social withdrawal. It tends to be the most severe of the schizophrenia subtypes and is often associated with poor premorbid personality and early and insidious onset. This subtype has been eliminated from DSM–5. Historically, and in other classifications, it is known as hebephrenia or hebephrenic schizophrenia.