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Schizophrenia
is a
psychiatric
diagnosis
denoting
a
persistent,
often
chronic,
mental
illness
variously
affecting
behavior,
thinking,
and
emotion.
The
status
of
schizophrenia
is
controversial,
largely
due to
the lack
of
objective
criteria
for
diagnosis
and the
subsequent
difficulty
in
adequately
researching
an
inadequately
defined
condition.
Research
has
suggested
however,
that
both
genetic
and
social
influences
are
important
contributing
factors.
Schizophrenia
is
commonly,
but
usually
incorrectly,
assumed
to
involve
a 'split
personality'.
Schizophrenia
is most
commonly
characterized
by both
'positive
symptoms'
(those
additional
to
normal
experience
and behaviour)
and
'negative
symptoms'
(the
lack or
decline
in
normal
experience
or behaviour).
Positive
symptoms
are
grouped
under
the
umbrella
term
psychosis
and
typically
include
delusions,
hallucinations,
and
thought
disorder.
Negative
symptoms
may
include
inappropriate
emotional
displays
or flat
emotional
affect,
poverty
of
speech,
and lack
of
motivation.
Some
models
of
schizophrenia
include
thought
disorder
and
planning
problems
in a
third
grouping,
the
'disorganization
syndrome'.
Additionally, neurocognitive
deficits
may be
present.
These
take the
form of
reduction
or
impairment
in basic
psychological
functions
such as
memory,
attention,
problem
solving,
executive
function
and
social
cognition.
The
onset is
typically
in late
adolescence
and
early
adulthood,
with
males
tending
to show
symptoms
earlier
than
females.
The
diagnostic
approach
to
schizophrenia
has been
opposed,
most
notably
by the
anti-psychiatry
movement,
who
argue
that
classifying
specific
thoughts
and behaviours
as
illness
allows
social
control
of
people
that
society
finds
undesirable
but who
have
committed
no
crime.
More
recently,
it has
been
argued
that
schizophrenia
is just
one end
of a
spectrum
of
experience
and behaviour,
and
everybody
in
society
may have
some
such
experiences
in their
life.
This is
known as
the
'continuum
model of
psychosis'
or the
'dimensional
approach'
and is
most
notably
argued
for by
psychologist
Richard
Bentall
and
psychiatrist
Jim van
Os.
Although
no
definite
causes
of
schizophrenia
have
been
identified,
most
researchers
and
clinicians
currently
believe
that
schizophrenia
is
primarily
a
disorder
of the
brain.
It is
thought
that
schizophrenia
may
result
from a
mixture
of
genetic
disposition
(genetic
studies
using
various
techniques
have
shown
relatives
of
people
with
schizophrenia
are more
likely
to show
signs of
schizophrenia
themselves)
and
environmental
stress
(research
suggests
that
stressful
life
events
may
precede
a
schizophrenic
episode).
It is
also
thought
that
processes
in early
neurodevelopment
are
important,
particularly
those
that
occur
during
pregnancy.
In adult
life,
particular
importance
has been
placed
upon the
function
(or
malfunction)
of
dopamine
in the
mesolimbic
pathway
in the
brain.
This
theory,
known as
the
dopamine
hypothesis
of
schizophrenia
largely
resulted
from the
accidental
finding
that a
drug
group
which
blocks
dopamine
function,
known as
the phenothiazines,
reduced
psychotic
symptoms.
These
drugs
have now
been
developed
further
and
antipsychotic
medication
is
commonly
used as
a first
line
treatment.
However,
this
theory
is now
thought
to be
overly
simplistic
as a
complete
explanation.
Differences
in
brain
structure
have
been
found
between
people
with
schizophrenia
and
those
without.
However,
these
tend
only to
be
reliable
on the
group
level
and, due
to the
significant
variability
between
individuals,
may not
be
reliably
present
in any
particular
individual.
Signs and Symptoms of Schizophrenia
Like many mental illnesses, the symptoms
of schizophrenia are based upon the behaviour of the person being assessed.
There is a list of diagnostic criteria which
must be met for a person to be so diagnosed.
These depend on both the presence and
duration of certain signs and symptoms. The
most commonly-used criteria for diagnosing
schizophrenia are from the American
Psychiatric Association's Diagnostic and
Statistical Manual of Mental Disorders (DSM)
and the World Health Organisation's
International Statistical Classification of
Diseases and Related Health Problems (ICD).
The most recent versions are ICD-10 and
DSM-IV-TR.
Below is an abbreviated version
of the diagnostic criteria from the DSM-IV-TR.
To be diagnosed as having
schizophrenia,
a person must display:
- A) Characteristic
schizophrenia
symptoms: Two or more of the following,
each present for a significant portion of
time during a one-month period (or less,
if successfully treated)
- delusions
- hallucinations
- disorganized speech (e.g., frequent
derailment or incoherence). See thought
disorder.
- grossly disorganized or catatonic
behavior
- negative symptoms, i.e., affective
flattening (lack or decline in emotional
response), alogia (lack or decline in
speech), or avolition (lack or decline in
motivation).
Note: Only one Criterion A symptom is
required if delusions are bizarre or
hallucinations consist of hearing voices.
- B) Social/occupational dysfunction:
For a significant portion of the time
since the onset of the disturbance, one or
more major areas of functioning such as
work, interpersonal relations, or
self-care, are markedly below the level
achieved prior to the onset.
- C) Duration: Continuous signs of the
disturbance persist for at least six
months. This six-month period must include
at least one month of symptoms (or less,
if successfully treated) that meet
Criterion A.
Historically,
schizophrenia in the West
was classified into simple, catatonic,
hebephrenic, and paranoid. The DSM now
contains five sub-classifications of
schizophrenia. These are:
- catatonic type (where marked absences
or peculiarities of movement are present),
- disorganized type (where thought
disorder and flat or inappropriate affect
are present together),
- paranoid type (where delusions and
hallucinations are present but thought
disorder, disorganized behaviour, and
affective flattening is absent),
- residual type (where positive symptoms
are present at a low intensity only) and
- undifferentiated type (psychotic
symptoms are present but the criteria for
paranoid, disorganized, or catatonic types
has not been met).
Some symptoms of
schizophrenia may also be
described as 'positive symptoms' (those
additional to normal experience and
behaviour) and negative symptoms (the lack
or decline in normal experience or behaviour).
'Positive symptoms' describe psychosis and
typically include delusions, hallucinations
and thought disorder. 'Negative symptoms'
describe inappropriate or nonpresent
emotion, poverty of speech, and lack of
motivation. In three-factor models of
schizophrenia, a third symptom grouping, the
so called 'disorganisation syndrome' is also
given. This considers thought disorder and
related disorganized behaviour to be in a
separate symptom cluster from delusions and
hallucinations.
Some schizophrenia symptoms, such as
social isolation, may be caused or appear to
be caused by a reaction of the individual to
avoid psychosis or other more severe
symptoms that are inconvenient or
unbearable. The person may place limits on
his environment or on his own behaviour
intended to avoid or limit whatever he
experiences as causes for these symptoms.
These limits or the resulting behaviour may
appear strange or inappropriate to other
people.
It is worth noting that many of the
positive or psychotic symptoms may occur in
a variety of disorders and not only in
schizophrenia. The psychiatrist Kurt
Schneider tried to list the particular forms
of psychotic symptoms which he thought were
particularly useful in distinguishing
between schizophrenia and other disorders
which could produce psychosis. These are
called first rank symptoms or Schneiderian
first rank symptoms and include delusions of
being controlled by an external force, the
belief that thoughts are being inserted or
withdrawn from your conscious mind, the
belief that your thoughts are being
broadcast to other people and hearing
hallucinated voices which comment on your
thoughts or actions, or may have a
conversation with other hallucinated voices.
As with other diagnostic methods, the
reliability of 'first rank symptoms' has
been questioned, although they remain in use
as diagnostic criteria in many countries.
How to
Diagnose
Schizophrenia
It has been argued that the diagnostic
approach to schizophrenia is flawed, as it
relies on an assumption of a clear dividing
line between what is considered to be mental
illness (fulfilling the diagnostic criteria)
and mental health (not fulfilling the
criteria). Recently it has been argued,
notably by psychiatrist Jim van Os and
psychologist Richard Bentall, that this
makes little sense, as studies have shown
that psychotic symptoms are present in many
people who never become 'ill' in the sense
of feeling distressed, becoming disabled in
some way or needing medical assistance.
Of particular concern is that the
decision as to whether a symptom is present
is a subjective decision by the person
making the diagnosis or relies on an
incoherent definition (for example, see the
entries on delusions and thought disorder
for a discussion of this issue). More
recently, it has been argued that psychotic
symptoms are not a good basis for making a
diagnosis of schizophrenia as "psychosis is
the 'fever' of mental illness — a serious
but nonspecific indicator".
Perhaps because of these factors, studies
examining the diagnosis of schizophrenia
have typically shown relatively low, or
inconsistent levels of diagnostic
reliability. Most famously, David Rosenhan's
1972 study, published as On being sane in
insane places, demonstrated that the
diagnosis of schizophrenia was (at least at
the time) often subjective and unreliable.
More recent studies have found agreement
between any two psychiatrists when
diagnosing schizophrenia tends to reach
about 65% at best. This, and the results of
earlier studies of diagnostic reliability
(which typically reported even lower levels
of agreement) have led some critics to argue
that the diagnosis of schizophrenia should
be abandoned.
Proponents have argued for a new approach
that would use the presence of specific
neurocognitive deficits to make a diagnosis.
These often accompany schizophrenia and take
the form of a reduction or impairment in
basic psychological functions such as
memory, attention, executive function and
problem solving. It is these sorts of
difficulties, rather than the psychotic
symptoms (which can in many cases be
controlled by antipsychotic medication),
which seem to be the cause of most
disability in schizophrenia. However, this
argument is relatively new and it is
unlikely that the method of diagnosing
schizophrenia will change radically in the
near future.
The diagnostic approach to
schizophrenia
has also been opposed by the anti-psychiatry
movement, who argue that classifying
specific thoughts and behaviours as an
illness allows social control of people that
society finds undesirable but who have
committed no crime. They argue that this is
a way of unjustly classifying a social
problem as a medical one to allow the
forcible detention and treatment of people
displaying these behaviours, which is
something which can be done under mental
health legislation in most western
countries.
An example of this can be seen in the
former Soviet Union, where an additional
sub-classification of sluggishly progressing
schizophrenia was created. Particularly in
the RSFSR (Russian Soviet Federated
Socialist Republic) this diagnosis was used
for the purpose of silencing political
dissidents or forcing them to recant their
ideas by the use of forcible confinement and
treatment. In 2000 similar concerns about
the abuse of psychiatry to unjustly silence
and detain members of the Falun Gong
movement by the Chinese government led the
American Psychiatric Association's Committee
on the Abuse of Psychiatry and Psychiatrists
to pass a resolution to urge the World
Psychiatric Association to investigate the
situation in China.
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