Independently, the term periodic catatonia is sometimes used in modern literature to describe a syndrome of recurrent phases of acute catatonia (excited or inhibited type) with full remission between episodes, which resembles the description of "motility psychosis" in the Wernicke-Kleist-Leonhard school. System catatonias or systematic catatonias are only defined in the Wernicke-Kleist-Leonhard school. These are chronic-progressive conditions characterized by specific disturbances of volition and psychomotricity, leading to a dramatic decline of executive and adaptive functioning and ability to communicate. They are considered forms of schizophrenia but distinct from other schizophrenic conditions. Affective flattening and apparent loss of interests are common but may be related to reduced emotional expression rather than lack of emotion. Heredity is low. Of the 21 different forms (6 "simple" and 15 "combined" forms) that have been described, most overlap only partially - if at all - with current definitions of either catatonia or schizophrenia, and thus are difficult to classify according to modern diagnostic manuals. Early childhood catatonias are also a diagnosis exclusive to the Wernicke-Kleist-Leonhard school, and refers to system catatonias that manifest in young children. Clinically, these conditions resemble severe regressive forms of autism. Chronic catatonia-like breakdown or Autistic catatonia refers to a functional decline seen in some patients with pre-existing autism spectrum disorder and/or intellectual disability which usually runs a chronic-progressive course and encompasses attenuated catatonic symptoms as well as mood and anxiety symptoms that increasingly interfere with adaptive functioning. Onset is typically insidious and often mistaken for background autistic symptoms.
Simple-type schizophrenia is a sub-type of schizophrenia included in the International Classification of Diseases (ICD-10), in which it is classified as a mental and behaviour disorder. It is not included in the current Diagnostic and Statistical Manual of Mental Disorders (DSM-5) or the upcoming ICD-11, effective on the 1st of January 2022. Simple-type schizophrenia is characterized by negative ("deficit") symptoms, such as avolition, apathy, anhedonia, reduced affect display, lack of initiative, lack of motivation, low activity; with absence of hallucinations or delusions of any kind. Simple schizophrenia was included as a proposed diagnosis for further study in the appendix of the former DSM-IV. Signs and symptoms
It has possibly the earliest onset compared to all other schizophrenias, considered to begin in some within childhood. Symptoms of schizophrenia simplex include an absence of will, impoverished thinking and flattening of affect. There is a gradual deterioration of functioning with increased amotivation and reduced socialization. It is considered to be rarely diagnosed and is a schizophrenia without psychotic symptoms.In a study of patients in a Massachusetts hospital, persons with simple schizophrenia were found to make attempts at reality fulfillment with respect to the more primitive needs; tending toward the achievement of fulfillment of these needs rather than engaging in fantasy as is typically found as a reaction to environmental stimuli by the psychotic person. Causes
A progressive state of simple schizophrenia results often in cases of adolescent onset juvenile general paresis. Paresis is caused by placental-foetal transfer of infection and results in intellectual (mental) subnormality.