The schizophrenia spectrum.
In psychiatric clinical practice, we most commonly encounter the following conditions: schizophrenic psychoses, schizoaffective disorders, delusional disorders, and organically caused psychoses (e.g. in the context of a neurological condition or substance-induced).
Characteristic of schizophrenia (prevalence approximately 0.5–1 % of the total population; men and women equally affected) are the following symptoms (at least one of the first four and two of the subsequent symptoms):
- the experience that one's own thoughts become audible, are inserted from outside, withdrawn, or broadcasted
- delusions (e.g. persecutory or referential delusions)
- auditory hallucinations in the form of commenting or dialoguing voices
- bizarre delusions (e.g. the delusional conviction of being a specific famous person)
- persistent hallucinations of any sensory modality
- disturbances of formal thinking, such as thought blocking, loosening of associations, tangential speech, or neologisms
- catatonic symptoms such as agitation, mutism, stupor
- negative symptoms such as affective flattening, poverty of speech, apathy, decreased social performance, alogia, attention disturbance, withdrawal
The course of schizophrenic psychoses may be episodic-remitting, episodic with increasing residual symptoms, or chronically deteriorating. We distinguish several subtypes of schizophrenia in current classification systems: paranoid (the most common worldwide), hebephrenic, catatonic, and undifferentiated.