Download Issues in diagnosis Sz 2012 new

Description of Issue
Evidence/Evaluation
Further commentary
Ethnic bias
Different criteria
This could reduce reliability and validity in
diagnosis. It is the idea that certain ethnic
groups may be more likely to be diagnosed
with a mental illness such as schizophrenia
than other ethnic groups, with essentially
the same symptoms. i.e. a bias in diagnosis.
Evidence supports the existence of this bias.
Keith et al. (1991) found that 2.1 % of African
Americans are diagnosed with sz, compared
with 1.4 % of White Americans. McGovern &
Cope (1987) reviewed the ethnicity of patients
in Birmingham mental hospitals: 2/3 of
psychotic patients were African-Caribbean,
compared with only 1/3 who were white or
Asian. This suggests.......
However, it could be argued that the evidence by
Keith is due to the fact that African-Americans are
more likely to live in poverty and to suffer marital
separation, suffer discrimination etc. Therefore, it
could be that these stressful life events trigger the
sz (the social causation hypothesis). Consequently,
there really is more sz in this ethnic group and
suggests that the diagnosis is valid.
Due to disagreement in the diagnosis of
schizophrenia between US and UK clinicians,
the diagnostic systems of DSM and ICD have
been made similar to avoid these diagnostic
differences. Whilst this has reduced
reliability problems, there are still differences
between the most recent versions E.g.
DSM requires symptoms to be evident for 6
months, ICD requires only 1 month
DSM V now has NO subtypes, ICD has 7
Another consequence of having different criteria
to diagnose schizophrenia is that it makes it
difficult to research studies. For example it is
then very difficult to compare data on treatment
outcomes since it is based on individuals
diagnosed with schizophrenia using different
criteria. This different starting point would act
as an extraneous variable and therefore result
in any research having reduced internal validity.
Since clinicians cannot agree on precisely what the
diagnosis of schizophrenia entails this suggests that
any definitions are arbitrary and likely to be only
temporary and therefore inconsistent.
Up until recently, the diagnosis of
schizophrenia could have been considered
invalid and unreliable. Due to the variety of
symptoms, course of the disorder and
response to treatments, 5 subtypes of
schizophrenia were developed to help
categorise patients. The issue here is that
patients considered ‘paranoid’ or ‘catatonic’
may have no symptoms in common and
therefore how could they be measuring the
same illness? This suggests it is not a valid
measuring tool.
To support this assumption, British psychiatrists
prefer to use the overarching name and
diagnosis of schizophrenia which suggests these
subtypes are incorrect and impractical.
Furthermore, this argument is backed up by the
fact that the new edition (DSM V) has removed
these subtypes due to their “low reliability, and
poor validity” (APA, 2013). Consequently, this
suggests this modern diagnostic tool should now
have increased validity and reliability and avoid
these issues. However, ICD 10 continues to use 7
subtypes of sz and therefore this issue is still
relevant.
This is the idea that a diagnostic and
classification system can predict the course
of the disorder and the outcome of any
treatment. If someone is given a diagnosis
of sz, it is expected that they should respond
to a particular drug. If they do not respond
this casts doubt on the validity of the
original diagnosis.
The fact that there are such differences in the
course of schizophrenia suggests that the
classification of this illness is perhaps incorrect.
For example, in terms of sz there is the rule of
1/3s where approximately 1/3 may have an
episode and not have any more, 1/3 may have
increasingly worse episodes intermittently and a
1/3 may not recover at all. This variety
suggests that the diagnosis of sz may not have
been correct.
In fact, research suggests that the predictive
validity of sz diagnoses is reasonably high.
However, Mason et al (1997) wanted to see what
would happen if they changed the duration
criterion to 1 month for the DSM and 6 months for
the ICD system. Whilst predictive validity was
reasonably high, it was higher for both when 6
months was used. This suggests that when using
the 1 month criterion, people with a one-off
disturbance are then incorrectly categorised as
having schizophrenia.
Diagnosis of a psychological disorder such as
sz can lead to the individual being labelled.
This can be stigmatising and have drastic
effects on their lives as other people are
often suspicious of such labels.
Furthermore, Szasz (1974) suggested that
mental illness is a myth and society uses this
stigmatising label in order to exclude nonconformists from society. Consequently,
being diagnosed with the label schizophrenia
can lead to negative effects for the sufferer.
However, the argument back would be that it is
not the label schizophrenia that leads to stigma.
People with mental disorders like sz were
stigmatised long before modern diagnostic
categories were used. Nevertheless, stigma can
only be reduced when there is better public
understanding of the true nature of the illness,
eg by events like sz awareness week by the
charity rethink.
However, the self-fulfilling prophecy idea could be
considered inadequate for such a serious disorder
as schizophrenia. Can we really suggest that
someone could conform to a label and then result
in intense symptoms such as hallucinations and
delusions? This seems illogical and therefore lacks
face validity.
This suggests that there will still be
inconsistency in diagnoses by clinicians using
different manuals.
Sub-types
Additionally, this problem still exists due to the
categorical approach of the diagnostic systems:
both ICD and DSM refer to schizophrenia-like
disorders for people who show symptoms of
schizophrenia but not enough to meet the exact
criteria. This demonstrates the difficulty with
diagnosing someone presenting with schizophrenialike symptoms and it has been suggested that that
sz is not an “all or nothing” condition as suggested
by the categorical diagnostic systems.
Predictive validity
Labelling
Moreover, an additional implication of being
given a label is that people could conform to the
label they are given. This is known as the selffulfilling prophecy (1966).
On the other hand, being labelled with an illness
such as schizophrenia is also advantageous as it
can then identify the appropriate treatment and
therefore help the individual.
Description of Issue
Ethnic bias
This could reduce reliability and validity in
diagnosis. It is the idea that certain ethnic
groups may be more likely to be
diagnosed with a mental illness such as
schizophrenia than other ethnic groups,
with essentially the same symptoms. i.e. a
bias in diagnosis.
Evidence/Evaluation
Evidence supports the existence of this bias.
Keith et al. (1991) found that 2.1 % of African
Americans are diagnosed with sz, compared with
1.4 % of White Americans. McGovern & Cope
(1987) reviewed the ethnicity of patients in
Birmingham mental hospitals: 2/3 of psychotic
patients were African-Caribbean, compared with
only 1/3 who were white or Asian. This
suggests.......
Further commentary
However, it could be argued that the evidence by
Keith is due to the fact that African-Americans are
more likely to live in poverty and to suffer marital
separation, suffer discrimination etc. Therefore, it
could be that these stressful life events trigger the
sz (the social causation hypothesis). Consequently,
there really is more sz in this ethnic group and
suggests that the diagnosis is valid.
Different criteria
Sub-types
Predictive validity
Labelling
Extension:
Why is it important to ensure there are no issues in the classification/diagnosis of schizophrenia? (Additional AO2)