Synonym Simple schizophrenia ICD-10 F20.6 | Specialty psychiatry ICD-9-CM 295.0 | |
Simple-type schizophrenia is a sub-type of schizophrenia as defined in the International Classification of Diseases (ICD-10). It is not included in the current Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
Contents
Other names for it are simple schizophrenia, simple deteriorative disorder, schizophrenia simplex, deficit schizophrenia or deficit syndrome.
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 suffering 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.
ICD
The WHO first listed the condition in ICD-6 (1949) and it stayed in the manual until the present version ICD-10. These are the current criteria:
The ICD is currently in revision and ICD-11 is expected to come out in 2018. In the preliminary Beta Draft version, there is no longer a diagnostic category of simple schizophrenia and all subtypes have been eliminated.
DSM
Simple-type schizophrenia also appeared in the first two editions of the DSM as an official diagnosis:
But after that, it was omitted in later versions and has since then never returned as a formal diagnosis in any DSM. However, DSM-IV (1994) and DSM-IV-TR (2000) included Simple Schizophrenia in the appendix under the proposed category of simple deteriorative disorder. The provisional research criteria for it were:
"Simple schizophrenia has perhaps the earliest age of onset, often first beginning in childhood, and shows very gradual and insidious progression over many years. Delusions, hallucinations, and loosening of associations are sparse, and indeed are for the most part absent. Rather the clinical picture is dominated by the annihilation of the will, impoverishment of thought, and flattening of affect. Gradually over the years these patients fall away from their former goals and often become cold and distant with their former acquaintances.
They may appear shiftless, and some are accused of laziness. Few thoughts disturb their days, and they may seem quite content to lie in bed or sit in a darkened room all day. Occasionally some bizarre behavior or a fragmentary delusion may be observed. For the most part, however, these patients do little to attract any attention; some continue to live with aged parents; others pass from one homeless mission."
Controversy
Definition of this type of schizophrenia is without unity or is controversial. The diagnosis was discontinued in the DSM system, although it was recommended for reinclusion. It was subsequently confirmed as having imprecise diagnostic criteria based on collective descriptions lacking in agreement.
However, in an experiment with a small sample size, five patients with a diagnosis of simple deteriorative disorder (DSM-IV) were found to have grey matter deficits, atrophy and reduced cerebral perfusion in the frontal areas. Whitwell et al. found justification to retain the classification on the basis of fulfillment of "dimensional" considerations of classification, as opposed to criticisms resulting from disagreement in considerations of classification using orientation from other categories.
Causes
A progressive state of simple dementia results often in cases of adolescent onset Juvenile general paresis. Paresis is being caused by placental-foetal transfer of infection and results in intellectual (mental) subnormality. Occurrence of this type of paresis is altogether uncommon (Lishman 1998).
History of definition
The early idea that a person with schizophrenia might present solely with symptoms and indications of deterioration (i.e. presenting with no accessory symptoms ) was identified as dementia simplex.
ICD-10 specifies the continuation of symptoms for a period of two years in the diagnosis of simple schizophrenia. This is because of disagreement on the classification validity of the sub-type, that having been retained by the ICD classification, has been omitted from DSM classifications. Symptoms identified earlier to dementia simplex are now DSM-attributed by way of improvements in diagnostic technique to other classifications such as neurodegenerative disorders.
Early observations that concur with symptoms of the dementia praecox of the form classified later as simplex began in 1838 with Jean Esquirol. In 1860, Bénédict Morel introduced the term dementia précoce and Langdon Down provided in 1887 the most complete description to that date of the clinical manifestation that Charpentier described in 1890 as dementia précoce simple des enfant normaux.
The description of simple schizophrenia is inter-changeable with describing symptoms as a form of dementia praecox known as simple dementing, at least in the time when the swiss psychiatrists Otto Diem and Eugen Bleuler were studying it. In 1893, Emil Kraepelin considered there were four types of schizophrenia, and was amongst the first to identify three of them (dementia hebephrenica, dementia paranoides, dementia catatonica). The simplex type was added by Eugen Bleuler to the earlier ones identified by Kraepelin in 1899 and subsequently given a basic outline in 1903 by Otto Diem publishing a monograph on dementia praecox in the simple dementing form. This was based on a survey of two males having had a relatively normal childhood but who then fell into patterns of living tending towards vagrancy.
A description of a cerebral disorder in relation to organic factors and in the context of general paralysis of the insane only; with no reference to schizophrenia, shows a disorder with features of generalized dementia (Lishman 1998). In 1951, a film was made showing the clinical characteristics of simple-type schizophrenia.