<unk>  is a subtype of<unk>  as defined in the Diagnostic and Statistical Manual of Mental Disorders. This type is characterized by prominent<unk>  behavior and speech (see formal thought disorder), and flat or inappropriate emotion and affect. Furthermore, the criteria for the catatonic subtype of<unk>  must not have been met. This type of<unk>  is also known as hebephrenia, and is named after the Greek goddess of youth, Hebe, in reference to the typical age of onset in puberty.
Unlike the paranoid subtype of<unk> , delusions and hallucinations are not the most prominent feature, although fragmentary delusions and hallucinations may be present.
The emotional responses of people diagnosed with this subtype can often seem strange or inappropriate to the situation. Inappropriate facial responses may be common and behavior is sometimes described as 'silly'. Complete lack of expressed emotion is sometimes seen, as is an apparent indifference, anhedonia (the lack of pleasure), and avolition (a lack of motivation). Some of these features are also present in other types of<unk> , but they are most prominent in<unk> .
This form of<unk>  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.<unk>  is thought to be an extreme expression of the 'disorganization syndrome' that has been hypothesised to be one aspect of a three-factor model of symptoms in<unk>  The other factors being 'reality distortion' (involving delusions and hallucinations) and 'psychomotor poverty' (poverty of speech, lack of spontaneous movement and various aspects of blunting of emotion).
Disorganized schizophrenia
Paranoid Schizophrenia
Schizophrenia
Brief psychotic disorder
Schizophreniform disorder
Brief reactive psychosis
Schizoaffective disorder
Bipolar disorder mixed state