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The characteristics of schizophrenia
Schizophrenia is characterised by a profound disruption of cognition and emotion, which
affects a person's language, thought, perception, affect and even sense of self.
Diagnostic criteria
Symptoms of schizophrenia are divided into positive and negative symptoms. Positive
symptoms are those that appear to reflect an excess or distortion of normal functions.
Negative symptoms are those that appear to reflect a loss of normal functions. Under the
DSM-IV-TR, the diagnosis of schizophrenia requires at least a month of two or more
positive symptoms.
Positive Symptoms
· Delusions ­ Bizarre beliefs that seem real to the person with schizophrenia, but are not
· Experiences of control ­ The person may believe they are under control of an alien force
that has invaded their mind / body.
· Hallucinations ­ Bizarre, unreal perceptions of the environment (hearing voices, seeing
lights / objects / faces, smelling things, feeling things crawling on the skin).
· Disordered thinking ­ Feeling that thoughts are being inserted or withdrawn from the
mind. May believe their thoughts are being broadcast.
Negative Symptoms
· Affective Flattening ­ A reduction in the range and intensity of emotional expression,
facial expression, voice tone, eye contact and body language.
· Alogia ­ Poverty of speech, less fluent and productive, showing blocked thoughts.
· Avolition ­ The reduction of / inability to have goal-directed behaviour.…read more

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In search of schizophrenia: Can psychiatrists agree on the same diagnosis when
independently assessing patients? The publication on the DSM-III was designed to
provide a more reliable system for classifying psychiatric disorders. This lead to claims of
a reliable classification system, leading to a much greater agreement of who did and didn'
t have schizophrenia. However 30 years later there is still little evidence that the DSM is
routinely used. Whaley (2001) found that inter-rater reliability in correlations of
diagnosis was as low as 0.11.
Unreliable symptoms: Klosterkötter et al assessed 489 admissions to a psychiatric unit to
determine whether positive or negative symptoms were more suited for the
determination of a diagnosis of schizophrenia. They found that positive symptoms were
more useful for diagnosis than negative symptoms. However it is also argued that a
diagnosis of schizophrenia is too different for each individual, that diagnostic categories
are not useful. 50 senior psychiatrists were asked to define between `bizarre' and `non-
bizarre' symptoms the inter-rater reliability correlations were only around 0.40,
concluding that the central diagnostic lack sufficient reliability for it to be a reliable
method for defining schizophrenic patients.
If scientists cannot agree who has schizophrenia (low reliability) then this raises questions of
what actually is (validity) schizophrenia.
Symptoms: Schneider listed all the psychotic symptoms that he believed distinguished
schizophrenia from other psychotic disorders. (First rank symptoms, experiences of
control / disordered thinking / hallucinations). These symptoms of schizophrenia could
make diagnosis more reliable. Yet it has been pointed out that these symptoms are found
in depression / bi-polar disorder.
Prognosis: There is no evidence that people who are diagnosed with schizophrenia will share
the same outcomes. 20% recover to previous level of functioning, 10% achieve significant
and lasting improvement, 30% show some improvement with relapses. Therefore there is
little predictive validity ­ some people never recover from the disorder, though many do.…read more

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Genetic Factors­ Genetic Factors
Twin Studies
Family studies: Gottesman found individuals who have schizophrenia and determine
whether their biological relatives are affected more than non-biological relatives. These
A crucial
studies assumption
have established is that the environments
that schizophrenia is more of
Unaffected identical
common brain and
biological brain
of aare equivalent.
person Therefore
with schizophrenia. it is assumed
(Children (right)
with that the greater
a schizophrenic concordance
parent have a for
concordance between
rate of 46%),identical twins
this could be dueis to
On ofrearing
common greater genetic
the ventricles
patters similarity
of a person
or heredity.
rather than environmental
Twin studies: similarity.
Twins allow for researchers toJoseph
with found
investigate the that
schizophrenia identical
contribution are twins
of15% are
genetic andthan
treated more similarly, encounter the
environmental influences. If the identical twins same environments
normal. Theserate
concordance (doing
is higher things
than non-
identicaland experience
twins more `identity
then this suggests confusion'
that the similarity is due(frequently
seem to result in negative symptoms
to genetic being
factors. treated
Joseph at
the calculated
twins ratherthat the
than data
two from prior 2001 suggests
individuals) and that
as apposed have the concordance
non-identical rate
cognitive of identical
twins was
Therefore 40.4% and
Joseph non-identical
argues that the was 7.4%. However
differences more recent studies,
in concordance rates where
between the
disturbances and poorer responses to
researcher doesn't know whether the twins are identical or non-identical tended to report
identical and non-identical twins is due toantipsychotics. nothing other than the
It is possible that this
a lower concordance rate for identical twins (researcher bias), however despite this the
concordance rate factors. could
for identical twins is still higher be non-identical
than the result oftwins. poor brain
Adoption studies: Studies development or tissue damage, and
Because of the difficulties of environmental influences on those who share
A central assumption
genes and environment, of adoption studies is
studies of genetically these
related adoptees
individuals are
are the
who ones that
have been lead
apart i.e. The parents
are used. Tienari et who adopt
al whose a child
findings to
were the
whose mother
of of schizophrenia.
was schizophrenic
164 adoptees whose biologicalare
mothers were
no different to adiagnosed
adoptive with schizophrenia,
parents who adopt 11 also received
children a diagnosis
whose of schizophrenia,
background is
compared to 4 of the 197 adoptees born to non-schizophrenic
normal. Joseph claims that it is unlikely that this is the case, as potential mothers. These findings
conclude that the genetic liability to schizophrenia had been `decisively confirmed'.
adoptive parents would have been informed of the genetic background of
children prior to adoption.…read more

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The dopamine hypothesis
Dopamine is a neurotransmitter that operates in the brain. The dopamine hypothesis states
The dopamine
that messages fromhypothesis
neurons that transmit dopamine fire too easily or often, leading to the
characteristic symptoms of schizophrenia.
Post-mortem studies
Schizophrenics are thought to have abnormally high levels of D² receptors on receiving
neurons, resulting in more dopamine binding and therefore more neurons firing.
A problem with the dopamine hypothesis is that the drugs used to treat
Dopamine neurons
schizophrenia by play a key role
blocking in guiding
dopamine attention,
activity can so disturbances
actually in this
increase itprocess
as the may
well lead
neurons to the problems
struggle relating for
to compensate to attention, perception
the deficiency. and thought
Haracz carriedfound
outin people
with schizophrenia. The key role played by dopamine in schizophrenia is as followed:
mortem studies of schizophrenics, and found that those who had received
· ­ This
drugs is a drug
shortly with death
before special had
our understanding
of dopamine of than
schizophrenia. It stimulates the nerve cells containing dopamine causing the synapse to
patients who weren't taking the drugs.
be flooded with dopamine. Large doses of the drug can cause hallucinations and
Antipsychotic neuro-imaging
Drugs research
­ These drugs block the activity of dopamine in the brain. By
reducing the neuro-imaging techniques
stimulation of dopamine, such
the drugs as PET symptoms
eliminate scans have failed
such as to
provide convincing
hallucinations evidence
and delusions. of altered
Because these dopamine activity
drugs can block in the
the action brains
of of and
eliminate with
individuals hallucinations and delusions,
schizophrenia. it suggests
(Copolov that dopamine
and Crook, 2000) is a contributory factor
to the disorder.
Parkinson's Disease ­ Low levels of dopamine are found in people who suffer from
Parkinson's disease. It was found that people who were taking the drug to raise their
A meta analysis
dopamine of were
levels, overhaving
90 CT scan studies
schizophrenic revealed (Grilly,
symptoms. that enlarged
2002) ventricles
may be due to the use of antipsychotic medication. A study by Lyon et al found
that as the dose of medication increased, the density of brain tissue decreased,
leading to enlarged ventricles.…read more

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Psychological Theories
This explanation
Freud of schizophrenia
(1924) believed acknowledges
that schizophrenia was thethe role
result ofof biological
two related factors in
causing the initial
regression to asensory
pre-ego experiences of schizophrenia,
stage and attempts but claims
to re-establish that further
ego control. If the
world ofof
the disorder
the appear as
schizophrenic hadindividuals attempt harsh,
been particularly to understand the their
for instance
parents wereWhen schizophrenics
cold or uncaring, an first experience
individual mayvoices / worrying
regress sensory
to this early stage
experiences, they turn to others
in their development beforeto confirm
the ego wasthe validity
properly of what
formed they
and are they
experiencing. Other a
have developed people fail
realistic to confirm
awareness ofthe
external of the experiences,
world. Freud saw so the
schizophrenia comes to believe
as an infantile that the
stage others
where are hiding
symptoms the truth.
such They begin
as delusions of to
reject feedback
grandeur from a
reflect those around
primitive them and
condition, develop
and delusional
symptoms such asbeliefs that they
are being manipulated
hallucinations by others.
reflecting the person's attempts to re-establish ego control.
Cognitive explanations
There isis no
lot research
of evidenceevidence to support
of a physical basis Freud's specific idea
for the cognitive of schizophrenia,
deficits associated
withexcept that many
schizophrenia. psychoanalysts
Research have claimed, like
by Meyer-Lindenberg him,
et al, that
found disordered
a link between
excess patterns
dopamine in are
the the cause for
prefrontal the disorder.
cortex and workingFromm-Reichmann described
memory. The suggestion
that `schizophrenogenic mothers'
`madness' is a consequence ofor families who
disbelieving are rejecting,
others overprotective,
receives support from a
recent suggestion andfrom
moralistic as contributory
treatment. Yellowlees influences to developing
et al have developed a machine
which produces virtual hallucinations, such as hearing the TV tell youpatients
schizophrenia. Studies have shown that parents of schizophrenic to kill act
yourself, or one from parents
person's faceof other kind
morphing of another.
into patients, Theparticularly
is to their
schizophrenic offspring is present (Oltmanns et al, 1999) but
schizophrenics that their hallucinations are not real. There is no evidence thatthis is likely toit
will be a consequence
produce of their
a successful children's problem.
treatment.…read more

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