Disorganized schizophrenia is thought to be an extreme expression of the disorganization syndrome that has been hypothesized to be one aspect of a three-factor model of symptoms in schizophrenia, the other factors being reality distortion (involving delusions and hallucinations) and psychomotor poverty (lack of speech, lack of spontaneous movement and various aspects of blunting of emotion).
The condition is also known as hebephrenia, named after the Greek term for "a boy" - hebeos, and possibly the ancient Greek goddess of youth, Hebe, daughter of Hera. The term refers to the ostensibly more prominent appearance of the disorder in persons around puberty.
The most prominent features of disorganized schizophrenia are not delusions and hallucinations, as they are in paranoid schizophrenia, although fragmentary delusions and hallucinations may be present. A person with disorganized schizophrenia may also experience behavioral disorganization, which may impair his or her ability to carry out daily activities such as showering or eating.
The emotional responses of such people often seem strange or inappropriate. Inappropriate facial responses may be common, and behavior is sometimes described as 'silly', such as inappropriate laughter. Sometimes there is a complete lack of emotion, including anhedonia (the lack of pleasure), and avolition (a lack of motivation). Some of these features are also present in other types of schizophrenia, but they are most prominent in disorganized schizophrenia.
This form of schizophrenia is typically associated with early onset (often between the ages of 15 and 25 years) and is thought to have a poor prognosis because of the rapid development of 'negative' symptoms and decline in social functioning.
^"The very great majority of cases [of dementia praecox] begin in the second or third decade ; 57 per cent, of the cases made use of in the clinical description began before the twenty-fifth year. This great predisposition of youth led Hecker to the name hebephrenia, "insanity of youth," for the group delimited by him ; Clouston also, who spoke of an " adolescent insanity," had evidently before everything dementia praecox in view. ... Hecker was even inclined to regard the issue of his hebephrenia just as an arrest of the whole psychic life on the developmental stage of the years of puberty. In fact, we find in silly dementia at least many features which are well known to us from the years of healthy development. Among these there is the tendency to unsuitable reading, the naive occupation of the mind with the "highest problems," the crude "readiness" of judgment, the pleasure in catch words and sounding phrases, also sudden changes of mood, depression and unrestrained merriment, occasional irritability and impulsiveness of action. Further the desultoriness of the train of thought, the half-swaggering, boastful, half-embarrassed, shy behaviour, the foolish laughing, the unsuitable jokes, the affected speech, the sought-out coarseness and the violent witticisms are phenomena which in healthy individuals, as in the patients, indicate that slight inward excitement which usually accompanies the changes of sexual development." From Kraepelin, EmilDementia praecox and paraphrenia, Chapter IX "Frequency and Causes", Chicago Medical Book. Co., (Text), 1919