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Adapted from WHO ICD-10 Criteria
The ICD-10 Classification
of Mental and Behavioural Disorders was published by the World Health Organization in 1992.
Definition
The schizophrenic disorders are characterized in general by fundamental and characteristic
distortions of thinking and perception, and by inappropriate or blunted affect.
Clear consciousness and
intellectual capacity are usually maintained, although certain cognitive deficits may evolve in the course
of time.
The disturbance involves
the most basic functions that give the normal person a feeling of individuality, uniqueness, and self-direction.
The most intimate thoughts,
feelings, and acts are often felt to be known to or shared by others, and explanatory delusions may develop, to the effect
that natural or supernatural forces are at work to influence the afflicted individual's thoughts and actions in ways that
are often bizarre. The individual may see himself or herself as the pivot of all that happens. Hallucinations, especially
auditory, are common and may comment on the individual's behaviour or thoughts.
Perception is frequently
disturbed in other ways: colours or sounds may seem unduly vivid or altered in quality, and irrelevant features of ordinary
things may appear more important than the whole object or situation.
Perplexity is also common
early on and frequently leads to a belief that everyday situations possess a special, usually sinister, meaning intended uniquely
for the individual.
In the characteristic schizophrenic
disturbance of thinking, peripheral and irrelevant features of a total concept, which are inhibited in normal directed mental
activity, are brought to the fore and utilized in place of those that are relevant and appropriate to the situation. Thus
thinking becomes vague, elleptical, and obscure, and its expression in speech sometimes incomprehensible. Breaks and interpolations
in the train of thought are frequent, and thoughts may seem to be withdrawn by some outside agency. Mood is characteristically
shallow, capricious, or incongruous. Ambivalence and disturbance of volition may appear as inertia, negativism, or stupor.
Catatonia may be present. The onset may be acute, with seriously disturbed behaviour, or insidious, with a gradual development
of odd ideas and conduct. The course of the disorder shows equally great variation and is by no means inevitably chronic or
deteriorating (the course is specified by five-character categories). In a proportion of cases, which may vary in different
cultures and populations, the outcome is complete, or nearly complete, recovery. The sexes are approximately equally affected
by the onset tends to be later in women.
Although no strictly pathognomonic
symptoms can be identified, for practical purposes it is useful to divide the above symptoms into groups that have special
importance for the diagnosis and often occur together, such as:
(a) thought echo, thought
insertion or withdrawal, and thought broadcasting;
(b) delusions of control, influence, or passivity, clearly referred to body or limb movements
or specific thoughts, actions, or sensations; delusional perception;
(c) hallucinatory voices giving a running commentary on the patient's behaviour, or discussing
the patient among themselves, or other types of hallucinatory voices coming from some part of the body;
(d) persistent delusions of other kinds that are culturally inappropriate and completely
impossible, such as religious or political identity, or superhuman powers and abilities (e.g. being able to control the weather,
or being in communication with aliens from another world);
(e) persistent hallucinations in any modality, when accompanied either by fleeting or half-formed
delusions without clear affective content, or by persistent over-valued ideas, or when occurring every day for weeks or months
on end;
(f) breaks or interpolations in the train of thought, resulting in incoherence or irrelevant
speech, or neologisms;
(g) catatonic behaviour, such as excitement, posturing, or waxy flexibility, negativism,
mutism, and stupor;
(h) "negative" symptoms such as marked apathy, paucity of speech, and blunting or incongruity
of emotional responses, usually resulting in social withdrawal and lowering of social performance; it must be clear that these
are not due to depression or to neuroleptic medication;
(i) a significant and consistent change in the overall quality of some aspects of personal
behaviour, manifest as loss of interest, aimlessness, idleness, a self-absorbed attitude, and social withdrawal.
Diagnostic Guidelines
The normal requirement for a diagnosis of schizophrenia is that a minimum
of one very clear symptom (and usually two or more if less clear-cut) belonging to any one of the groups listed as (a) to
(d) above, or symptoms from at least two of the groups referred to as (e) to (h), should have been clearly present for most
of the time during a period of 1 month or more. Conditions meeting such symptomatic requirements but of duration less than
1 month (whether treated or not) should be diagnosed in the first instance as acute schizophrenia-like psychotic disorder
and are classified as schizophrenia if the sumptoms persist for longer periods.
Viewed retrospectively,
it may be clear that a prodromal phase in which symptoms and behaviour, such as loss of interest in work, social activities,
and personal appearance and hygiene, together with generalized anxiety and mild degrees of depression and preoccupation, preceded
the onset of psychotic symptoms by weeks or even months. Because of the difficulty in timing onset, the 1-month duration criterion
applies only to the specific symptoms listed above and not to any prodromal nonpsychotic phase.
The diagnosis of schizophrenia
should not be made in the presence of extensive depressive or manic symptoms unless it is clear that schizophrenic symptoms
antedated the affective disturbance. If both schizophrenic and affective symptoms develop together and are evenly balanced,
the diagnosis of schizoaffective disorder should be made, even if the schizophrenic symptoms by themselves would have justified
the diagnosis of schizophrenia. Schizophrenia should not be diagnosed in the presence of overt brain disease or during states
of drug intoxication or withdrawal.
Paranoid Schizophrenia
Definition
This is the commonest type of schizophrenia in most parts
of the world. The clinical picture 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 not prominent.
Examples of the most common
paranoid symptoms are:
(a) delusions of persecution,
reference, exalted birth, special mission, bodily change, or jealousy;
(b) hallucinatory voices that threaten the patient or give commands, or auditory hallucinations
without verbal form, such as whistling, humming, or laughing;
(c) hallucinations of smell or taste, or of sexual or other bodily sensations; visual hallucinations
may occur but are rarely predominant.
Thought disorder may be
obvious in acute states, but if so it does not prevent the typical delusions or hallulcinations from being described clearly.
Affect is usually less blunted than in other varieties of schizophrenia, but a minor degree of incongruity is common, as are
mood disturbances such as irritability, sudden anger, fearfulness, and suspicion. "Negative" symptoms such as blunting of
affect and impaired volition are often present but do not dominate the clinical picture.
The course of paranoid
schizophrenia may be episodic, with partial or complete remissions, or chronic. In chronic cases, the florid symptoms persist
over years and it is difficult to distinguish discrete episodes. The onset tends to be later than in the hebephrenic and catatonic
forms.
Diagnostic Guidelines
The general criteria for a diagnosis of schizophrenia (see
introduction to F20 above) must be satisfied. In addition, hallucinations and/or delusions must be prominent, and disturbances
of affect, volition and speech, and catatonic symptoms must be relatively inconspicuous. The hallucinations will usually be
of the kind described in (b) and (c) above. Delusions can be of almost any kind of delusions of control, influence, or passivity,
and persecutory beliefs of various kinds are the most characteristic.
Includes:
* paraphrenic
schizophrenia
Differential diagnosis.
It is important to exclude epileptic and drug-induced psychoses, and to remember that persecutory delusions might carry little
diagnostic weight in people from certain countries or cultures.
Excludes:
* involutional
paranoid state (F22.8)
* paranoia (F22.0)
Hebephrenic Scizophrenia
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 inappropirate and often accompanied by giggling or self-satisfied, self-absorbed smiling, or by a lofty
manner, grimaces, mannerisms, pranks, hypochondriacal complaints, and reiterated phrases. Thought is disorganized and speech
rambling and incoherent. There is a tendency to remain solitary, and behaviour seems empty of purpose and feeling. This form
of schizphrenia usually starts between the ages of 15 and 25 years and tends to have a poor prognosis because of the rapid
development of "negative" symptoms, particularly flattening of affect and loss of volition.
In addition, disturbances
of affect and volition, and thought disorder are usually prominent. Hallucinations and delusions may be present but are not
usually prominent. Drive and determination are lost and goals abandoned, so that the patient's behaviour becomes characteristically
aimless and empty of purpose. A superficial and manneristic preoccupation with religion, philosophy, and other abstract themes
may add to the listener's difficulty in following the train of thought.
Diagnostic Guidelines
The general criteria for a diagnosis of schizophrenia must be
satisified. Hebephrenia should normally be diagnosed for the first time only in adolescents or young adults. The premorbid
personality is characteristically, but not necessarily, rather shy and solitary. For a confident diagnosis of hebephrenia,
a period of 2 or 3 months of continuous observation is usually necessary, in order to ensure that the characteristic behaviours
described above are sustained.
Includes:
* disorganized
schizophrenia
* hebephrenia
Catatonic Schizophrenia
Definition
Prominent psychomotor disturbances are essential and dominant
features and 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.
For reasons that are poorly
understood, catatonic schizophrenia is now rarely seen in industrial countries, though it remains common elsewhere. These
catatonic phenomena may be combined with a dream-like (oneiroid) state with vivid scenic hallucinations.
Diagnostic Guidelines
The general criteria for a diagnosis of schizophrenia (see introduction
to F20 above) must be satisfied. Transitory and isolated catatonic symptoms may occur in the context of any other subtype
of schizophrenia, but for a diagnosis of catatonic schizophrenia one or more of the following behaviours should dominate the
clinical picture:
(a) stupor (marked decrease
in reactivity to the environment and in spontaneous movements and activity) or mutism;
(b) excitement (apparently purposeless motor activity, not influenced by external stimuli);
(c) posturing (voluntary assumption and maintenance of inappropriate or bizarre postures);
(d) negativism (an apparently motiveless resistance to all instructions or attempts to
be moved, or movement in the opposite direction);
(e) rigidity (maintenance of a rigid posture against efforts to be moved);
(f) waxy flexibility (maintenance of limbs and body in externally imposed positions); and
(g) other symptoms such as command automatism (automatic compliance with instructions),
and perseveration of words and phrases.
In uncommunicative patients
with behavioural manifestations of catatonic disorder, the diagnosis of schizophrenia may have to be provisional until adequate
evidence of the presence of other symptoms is obtained. It is also vital to appreciate that catatonic symptoms are not diagnostic
of schizophrenia. A catatonic symptom or symptoms may also be provoked by brain disease, metabolic disturbances, or alcohol
and drugs, and may also occur in mood disorders.
Includes:
* catatonic
stupor
* schizophrenic catalepsy
* schizophrenic catatonia
* schizophrenic flexibilitas cerea
Undifferentiated Schizophrenia
Definition
Conditions meeting the general diagnostic criteria for
schizophrenia but not conforming to any of the above subtypes, or exhibiting the features of more than one of them without
a clear predominance of a particular set of diagnostic characteristics. This rubric should be used only for psychotic conditions
(i.e. residual schizophrenia and post-schizophrenic depression are excluded) and after an attempt has been made to classify
the condition into one of the three preceding categories.
Diagnostic Guidelines
This category should be reserved for disorders that:
(a) meet the diagnostic
criteria for schizophrenia;
(b) do not satisfy the criteria for the paranoid, hebephrenic, or catatonic subtypes;
(c)
do not satisfy the criteria for residual schizophrenia or post-schizophrenic depression.
Includes:
atypical
schizophrenia
Post Schizophrenic Depression
Definition
A depressive episode, which may be prolonged, arising in
the aftermath of a schizophrenic illness. Some schizophrenic symptoms must still be present but no longer dominate the clinical
picture. These persisting schizophrenic symptoms may be "positive" or "negative", though the latter are more common. It is
uncertain, and immaterial to the diagnosis, to what extent the depressive symptoms have merely been uncovered by the resolution
of earlier psychotic symptoms (rather than being a new development) or are an intrinsic part of schizophrenia rather than
a psychological reaction to it. They are rarely sufficiently severe or extensive to meet criteria for a severe depressive
episode, and it is often difficult to decide which of the patient's symptoms are due to depression and which to neuroleptic
medication or to the impaired volition and affective flattening of schizophrenia itself. This depressive disorder is associated
with an increased risk of suicide.
Diagnostic Guidelines
The diagnosis should be made only if:
(a) the patient has had
a schizophrenic illness meeting the general criteria for schizophrenia within the past 12 months;
(b) some schizophrenic symptoms are still present; and
(c) the depressive symptoms are prominent and distressing, fulfilling at least the criteria
for a depressive episode, and havew been present for at least 2 weeks.
If the patient no longer
has any schizophrenic symptoms, a depressive episode should be diagnosed. If schizophrenic symptoms are still florid and prominent,
the diagnosis should remain that of the appropriate schizophrenic subtype.
Chronic Undifferentiated Schizophrenia
Definition
A chronic stage in the development of a schizophrenic
disorder in which there has been a clear progression from an early stage (comprising one or more episodes with psychotic symptoms
meeting the general criteria for schizophrenia) to a later stage characterized by long-term, though not necessarily irreversible,
"negative" symptoms.
Diagnostic Guidelines
For a confident diagnosis, the following requirements should
be met:
(a) prominent "negative"
schizophrenic symptoms, i.e. 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;
(b) evidence in the past of at least one clear-cut psychotic episode meeting the diagnostic
criteria for schizophrenia;
(c) a period of at least 1 year during which the intensity and frequency of florid symptoms
such as delusions and hallucinations have been minimal or substantially reduced and the "negative" schizophrenic syndrome
has been present;
(d) absence of dementia or other organic brain disease or disorder, and of chronic depression
or institutionalism sufficient to explain the negative impairments.
If adequate information
about the patient's previous history cannot be obtained, and it therefore cannot be established that criteria for schizophrenia
have been met at some time in the past, it may be necessary to make a provisional diagnosis of residual schizophrenia.
Includes:
* chronic
undifferentiated schizophrenia
* "Restzustand"
* schizophrenic residual state
Simple schizophrenia
Definition
An uncommon 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.
Delusions and hallucinations are not evident, and the disorder is less obviously psychotic than the hebephrenic, paranoid,
and catatonic subtypes of schizophrenia. The characteristic "negative" features of residual schizophrenia (e.g. blunting of
affect, loss of volition) develop without being preceded by any overt psychotic symptoms. With increasing social impoverishment,
vagrancy may ensue and the individual may then become self-absorbed, idle, and aimless.
Diagnostic Guidelines
Simple schizophrenia is a difficult diagnosis to make with
any confidence because it depends on establishing the slowly progressive development of the characteristic "negative" symptoms
of residual schizophrenia without any history of hallucinations, delusions, or other manifestations of an earlier psychotic
episode, and with significant changes in personal behaviour, manifest as a marked loss of interest, idleness, and social withdrawal.
Includes:
* schizophrenia simplex
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