The ICD-10 Classification of Mental and Behavioural
Disorders
World Health Organization, Geneva, 1992
Schizophrenia
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and thoughts may seem to be withdrawn by some outside agency.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.
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)
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 (see
introduction to F20 above) 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
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
Conditions meeting the general diagnostic criteria for
schizophrenia (see introduction to F20 above) 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
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 (see introduction to F20 above)
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.
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 described above) 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
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
ICD-10 copyright © 1992 by World
Health Organization.
AZ Psychiatry copyright
© (www.azpsychiatry.info)
by Dr. Manaan Kar Ray
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