Chapter V
Mental and behavioural disorders
(F00-F99)

Schizophrenia, schizotypal and delusional disorders
(F20-F29)

Definition

This block brings together schizophrenia, as the most important member of the group, schizotypal disorder, persistent delusional disorders, and a larger group of acute and transient psychotic disorders. Schizoaffective disorders have been retained here in spite of their controversial nature.

F20 Schizophrenia

Definition

The schizophrenic disorders are characterized in general by fundamental and characteristic distortions of thinking and perception, and affects that are inappropriate or blunted. Clear consciousness and intellectual capacity are usually maintained although certain cognitive deficits may evolve in the course of time. The most important psychopathological phenomena include thought echo; thought insertion or withdrawal; thought broadcasting; delusional perception and delusions of control; influence or passivity; hallucinatory voices commenting or discussing the patient in the third person; thought disorders and negative symptoms.

The course of schizophrenic disorders can be either continuous, or episodic with progressive or stable deficit, or there can be one or more episodes with complete or incomplete remission. The diagnosis of schizophrenia should not be made in the presence of extensive depressive or manic symptoms unless it is clear that schizophrenic symptoms antedate the affective disturbance. Nor should schizophrenia be diagnosed in the presence of overt brain disease or during states of drug intoxication or withdrawal. Similar disorders developing in the presence of epilepsy or other brain disease should be classified under F06.2, and those induced by psychoactive substances under F10-F19 with common fourth character .5.

Excl.:
schizophrenia:
schizophrenic reaction ( F23.2)
schizotypal disorder ( F21)
F20.0 Paranoid schizophrenia
Definition

Paranoid schizophrenia is dominated by relatively stable, often paranoid delusions, usually accompanied by hallucinations, particularly of the auditory variety, and perceptual disturbances. Disturbances of affect, volition and speech, and catatonic symptoms, are either absent or relatively inconspicuous.

Incl.:
Paraphrenic schizophrenia
Excl.:
involutional paranoid state ( F22.8)
paranoia ( F22.0)
F20.1 Hebephrenic schizophrenia
Definition

A form of schizophrenia in which affective changes are prominent, delusions and hallucinations fleeting and fragmentary, behaviour irresponsible and unpredictable, and mannerisms common. The mood is shallow and inappropriate, thought is disorganized, and speech is incoherent. There is a tendency to social isolation. Usually the prognosis is poor because of the rapid development of "negative" symptoms, particularly flattening of affect and loss of volition. Hebephrenia should normally be diagnosed only in adolescents or young adults.

Incl.:
Disorganized schizophrenia
Hebephrenia
F20.2 Catatonic schizophrenia
Definition

Catatonic schizophrenia is dominated by prominent psychomotor disturbances that may alternate between extremes such as hyperkinesis and stupor, or automatic obedience and negativism. Constrained attitudes and postures may be maintained for long periods. Episodes of violent excitement may be a striking feature of the condition. The catatonic phenomena may be combined with a dream-like (oneiroid) state with vivid scenic hallucinations.

Incl.:
Catatonic stupor
Schizophrenic:
  • catalepsy
  • catatonia
  • flexibilitas cerea
F20.3 Undifferentiated schizophrenia
Definition

Psychotic conditions meeting the general diagnostic criteria for schizophrenia but not conforming to any of the subtypes in F20.0-F20.2, or exhibiting the features of more than one of them without a clear predominance of a particular set of diagnostic characteristics.

Incl.:
Atypical schizophrenia
Excl.:
acute schizophrenia-like psychotic disorder ( F23.2)
chronic undifferentiated schizophrenia ( F20.5)
post-schizophrenic depression ( F20.4)
F20.4 Post-schizophrenic depression
Definition

A depressive episode, which may be prolonged, arising in the aftermath of a schizophrenic illness. Some schizophrenic symptoms, either "positive" or "negative", must still be present but they no longer dominate the clinical picture. These depressive states are associated with an increased risk of suicide. If the patient no longer has any schizophrenic symptoms, a depressive episode should be diagnosed (F32.-). If schizophrenic symptoms are still florid and prominent, the diagnosis should remain that of the appropriate schizophrenic subtype (F20.0-F20.3).

F20.5 Residual schizophrenia
Definition

A chronic stage in the development of a schizophrenic illness in which there has been a clear progression from an early stage to a later stage characterized by long- term, though not necessarily irreversible, "negative" symptoms, e.g. psychomotor slowing; underactivity; blunting of affect; passivity and lack of initiative; poverty of quantity or content of speech; poor nonverbal communication by facial expression, eye contact, voice modulation and posture; poor self-care and social performance.

Incl.:
Chronic undifferentiated schizophrenia
Restzustand (schizophrenic)
Schizophrenic residual state
F20.6 Simple schizophrenia
Definition

A disorder in which there is an insidious but progressive development of oddities of conduct, inability to meet the demands of society, and decline in total performance. The characteristic negative features of residual schizophrenia (e.g. blunting of affect and loss of volition) develop without being preceded by any overt psychotic symptoms.

F20.8 Other schizophrenia
Incl.:
Cenesthopathic schizophrenia
Schizophreniform:
  • disorder NOS
  • psychosis NOS
Excl.:
brief schizophreniform disorders ( F23.2)
F20.9 Schizophrenia, unspecified

F21 Schizotypal disorder

Definition

A disorder characterized by eccentric behaviour and anomalies of thinking and affect which resemble those seen in schizophrenia, though no definite and characteristic schizophrenic anomalies occur at any stage. The symptoms may include a cold or inappropriate affect; anhedonia; odd or eccentric behaviour; a tendency to social withdrawal; paranoid or bizarre ideas not amounting to true delusions; obsessive ruminations; thought disorder and perceptual disturbances; occasional transient quasi-psychotic episodes with intense illusions, auditory or other hallucinations, and delusion-like ideas, usually occurring without external provocation. There is no definite onset and evolution and course are usually those of a personality disorder.

Incl.:
Latent schizophrenic reaction
Schizophrenia:
  • borderline
  • latent
  • prepsychotic
  • prodromal
  • pseudoneurotic
  • pseudopsychopathic
Schizotypal personality disorder
Excl.:
Asperger syndrome ( F84.5)
schizoid personality disorder ( F60.1)

F22 Persistent delusional disorders

Definition

Includes a variety of disorders in which long-standing delusions constitute the only, or the most conspicuous, clinical characteristic and which cannot be classified as organic, schizophrenic or affective. Delusional disorders that have lasted for less than a few months should be classified, at least temporarily, under F23.-.

F22.0 Delusional disorder
Definition

A disorder characterized by the development either of a single delusion or of a set of related delusions that are usually persistent and sometimes lifelong. The content of the delusion or delusions is very variable. Clear and persistent auditory hallucinations (voices), schizophrenic symptoms such as delusions of control and marked blunting of affect, and definite evidence of brain disease are all incompatible with this diagnosis. However, the presence of occasional or transitory auditory hallucinations, particularly in elderly patients, does not rule out this diagnosis, provided that they are not typically schizophrenic and form only a small part of the overall clinical picture.

Incl.:
Paranoia
Paranoid:
  • psychosis
  • state
Paraphrenia (late)
Sensitiver Beziehungswahn
Excl.:
paranoid:
  • personality disorder (F60.0)
  • psychosis, psychogenic (F23.3)
  • reaction (F23.3)
  • schizophrenia (F20.0)
F22.8 Other persistent delusional disorders
Definition

Disorders in which the delusion or delusions are accompanied by persistent hallucinatory voices or by schizophrenic symptoms that do not justify a diagnosis of schizophrenia (F20.-).

Incl.:
Delusional dysmorphophobia
Involutional paranoid state
Paranoia querulans
F22.9 Persistent delusional disorder, unspecified

F23 Acute and transient psychotic disorders

Definition

A heterogeneous group of disorders characterized by the acute onset of psychotic symptoms such as delusions, hallucinations, and perceptual disturbances, and by the severe disruption of ordinary behaviour. Acute onset is defined as a crescendo development of a clearly abnormal clinical picture in about two weeks or less. For these disorders there is no evidence of organic causation. Perplexity and puzzlement are often present but disorientation for time, place and person is not persistent or severe enough to justify a diagnosis of organically caused delirium (F05.-). Complete recovery usually occurs within a few months, often within a few weeks or even days. If the disorder persists, a change in classification will be necessary. The disorder may or may not be associated with acute stress, defined as usually stressful events preceding the onset by one to two weeks.

F23.0 Acute polymorphic psychotic disorder without symptoms of schizophrenia
Definition

An acute psychotic disorder in which hallucinations, delusions or perceptual disturbances are obvious but markedly variable, changing from day to day or even from hour to hour. Emotional turmoil with intense transient feelings of happiness or ecstasy, or anxiety and irritability, is also frequently present. The polymorphism and instability are characteristic for the overall clinical picture and the psychotic features do not justify a diagnosis of schizophrenia (F20.-). These disorders often have an abrupt onset, developing rapidly within a few days, and they frequently show a rapid resolution of symptoms with no recurrence. If the symptoms persist the diagnosis should be changed to persistent delusional disorder (F22.-).

Incl.:
Bouffée délirante without symptoms of schizophrenia or unspecified
Cycloid psychosis without symptoms of schizophrenia or unspecified
F23.1 Acute polymorphic psychotic disorder with symptoms of schizophrenia
Definition

An acute psychotic disorder in which the polymorphic and unstable clinical picture is present, as described in F23.0; despite this instability, however, some symptoms typical of schizophrenia are also in evidence for the majority of the time. If the schizophrenic symptoms persist the diagnosis should be changed to schizophrenia (F20.-).

Incl.:
Bouffée délirante with symptoms of schizophrenia
Cycloid psychosis with symptoms of schizophrenia
F23.2 Acute schizophrenia-like psychotic disorder
Definition

An acute psychotic disorder in which the psychotic symptoms are comparatively stable and justify a diagnosis of schizophrenia, but have lasted for less than about one month; the polymorphic unstable features, as described in F23.0, are absent. If the schizophrenic symptoms persist the diagnosis should be changed to schizophrenia (F20.-).

Incl.:
Acute (undifferentiated) schizophrenia
Brief schizophreniform:
  • disorder
  • psychosis
Oneirophrenia
Schizophrenic reaction
Excl.:
organic delusional [schizophrenia-like] disorder ( F06.2)
schizophreniform disorders NOS ( F20.8)
F23.3 Other acute predominantly delusional psychotic disorders
Definition

Acute psychotic disorders in which comparatively stable delusions or hallucinations are the main clinical features, but do not justify a diagnosis of schizophrenia (F20.-). If the delusions persist the diagnosis should be changed to persistent delusional disorder (F22.-).

Incl.:
Paranoid reaction
Psychogenic paranoid psychosis
F23.8 Other acute and transient psychotic disorders
Definition

Any other specified acute psychotic disorders for which there is no evidence of organic causation and which do not justify classification to F23.0-F23.3.

F23.9 Acute and transient psychotic disorder, unspecified
Incl.:
Brief reactive psychosis NOS
Reactive psychosis

F24 Induced delusional disorder

Definition

A delusional disorder shared by two or more people with close emotional links. Only one of the people suffers from a genuine psychotic disorder; the delusions are induced in the other(s) and usually disappear when the people are separated.

Incl.:
Folie à deux
Induced:
  • paranoid disorder
  • psychotic disorder

F25 Schizoaffective disorders

Definition

Episodic disorders in which both affective and schizophrenic symptoms are prominent but which do not justify a diagnosis of either schizophrenia or depressive or manic episodes. Other conditions in which affective symptoms are superimposed on a pre-existing schizophrenic illness, or co-exist or alternate with persistent delusional disorders of other kinds, are classified under F20-F29. Mood-incongruent psychotic symptoms in affective disorders do not justify a diagnosis of schizoaffective disorder.

F25.0 Schizoaffective disorder, manic type
Definition

A disorder in which both schizophrenic and manic symptoms are prominent so that the episode of illness does not justify a diagnosis of either schizophrenia or a manic episode. This category should be used for both a single episode and a recurrent disorder in which the majority of episodes are schizoaffective, manic type.

Incl.:
Schizoaffective psychosis, manic type
Schizophreniform psychosis, manic type
F25.1 Schizoaffective disorder, depressive type
Definition

A disorder in which both schizophrenic and depressive symptoms are prominent so that the episode of illness does not justify a diagnosis of either schizophrenia or a depressive episode. This category should be used for both a single episode and a recurrent disorder in which the majority of episodes are schizoaffective, depressive type.

Incl.:
Schizoaffective psychosis, depressive type
Schizophreniform psychosis, depressive type
F25.2 Schizoaffective disorder, mixed type
Incl.:
Cyclic schizophrenia
Mixed schizophrenic and affective psychosis
F25.8 Other schizoaffective disorders
F25.9 Schizoaffective disorder, unspecified
Incl.:
Schizoaffective psychosis NOS

F28 Other nonorganic psychotic disorders

Definition

Delusional or hallucinatory disorders that do not justify a diagnosis of schizophrenia (F20.-), persistent delusional disorders (F22.-), acute and transient psychotic disorders (F23.-), psychotic types of manic episode (F30.2), or severe depressive episode (F32.3).

Incl.:
Chronic hallucinatory psychosis

F29 Unspecified nonorganic psychosis

Incl.:
Psychosis NOS
Excl.:
mental disorder NOS ( F99)
organic or symptomatic psychosis NOS ( F09)