The best way to tackle this question is to have 3 main points
Whats the issue? AO1
Why is this an issue? AO2
What is the implication of it? AO2
Whats the issue? Lack of Inter-Rater Reliability
One issues related to the classification and diagnosis of schizophrenia is reliability. This refers to the consistency of a measuring instrument, such as the DSM or ICD that is used when classifying and diagnosing schizophrenia. Reliability can either be measured in terms of inter-rater reliability, which is the extent to which two or more independent assessors give a similar diagnosis, or in terms of test-retest reliability which is the extent to which the tests used to deliver these diagnoses are consistent over time.
Why is this an issue?
Beck et al looked at the inter rater reliability between psychiatrists when considering the cases of 154 patients. Th reliability was only 54%- meaning they only agreed on a diagnosis for 54% of the 154 patients.
Although it has been claimed that the DSM (version three) onwards is reliable, evidence shows that the reliability of the DSM is low when assessed by inter-rater reliability. For example Whaley (2001) found only a small positive correlation of +.11 between different raters. This is evidence for low reliability when using the DSM to diagnose schizophrenia. However, test-retest reliability studies have shown positive results. Prescott et al (1986) analysed the test-retest reliability of several measures of attention and information processing in 14 chronic schizophrenics. Performance on these measures was stable over a 6-month period. This shows that there is high test-retest reliability when using these measures of attention and information processing to diagnose schizophrenia
Implications
Differences in cultural interpretations also pose a threat to the reliability of the diagnosis of schizophrenia. A research study by Copeland et al (1971) compared 134 US psychiatrists and 194 British psychiatrists in their diagnosis of a patient, and found that 69% of the US psychiatrists diagnosed schizophrenia compared with only 2% of the British psychiatrists. This suggests that there is massive variation between countries and it affects the reliability of diagnosis in schizophrenia.
Original author of this point can be found here: http://www.scribd.com/doc/181173375/discuss-issues-relating-to-the-diagnosis-and-classification-of-schizophrenia-essay-for-unit-4-A-level-Psychology-AQA-A-typical-essay-they-love-to-as
Whats the issue?- Reliability
Realibility of DSM and ICD is poor, as the categories of disorders are not valid. There is no real evidence that 'biochemical imbalances are the cause or effect of mental illness'. (Psychology Review 2014)
Why is this an issue?
Incorrect diagnosis is probably the result of problems with defining schizophrenia, e.g. if you can't classify schizophrenia how can you diagnose it?
Rosenhan's research involved eight healthy individuals giving a false account of symptoms to the psychiatrist. He found that all eight patients were admitted to a psychiatric hospital on the basis of their fake symptoms. Seven out of eight were diagnosed as schizophrenic.
Implications
Thus people who do not have schizophrenia may be included in research which may result in invalid conclusions about the illness' cause and or treatment.
Various scientists have argued that the DSM-5 forces clinicians to make distinctions that are not supported by solid evidence, distinctions that have major treatment implications, including drug prescriptions and the availability of health insurance coverage.
Having said that: The DSM now has a multi-axial format. Clinicians must assess patients in 5 separate axes before reaching a conclusion. The fact that these axes cover biological, social and psychological aspects of the patient's condition ensures that a holistic view of symptoms experienced is considered. Providing a more holistic approach increases the chances of more effective and specific treatment for the patient.
If there is no firm evidence for the theory that people are suffering from medical illness that can be diagnosed by doctors, then everything else is up for question- what kind of professionals do we need? what should the main treatments be?
What's the issue?- Low descriptive validity
When measuring descriptive validity, it can be difficult to distinguish the boundaries between schizophrenia and other distinct mental disorders due to dual diagnosis and the overlap of symptoms e.g. distinguishing schizophrenia and depression.
An assessment for schizophrenia has good criterion validity if those diagnosed differ in predictable ways from those not diagnosed, e.g. social problems. However, this will be true for all mental disorders, and so it does not isolate schizophrenia only.
Low predictive validity
Predictive validity is an issue with schizophrenia because the outcomes for schizophrenia are highly variable. It is also difficult to predict the response to treatment as all indiviiudals respond differently; some schizophrenics may respond positively to anti-psychotic drugs, whilst other will not.
Why is this an issue?
This makes it complicated for practitioners to identify the correct illness, especially when individuals suffer from co-morbidity. As symptoms of different disorders often have common characteristics, it is difficult to identify exactly which symptoms reflects which disorder. Sim et al, who studied 142 hospitalised schizophrenic patients, found that 32% had an additional mental disorder.
New scientist (2013) also claim "there is no reason to believe that DSM-5 is safe or scientifically sound"
Implications
This is a weakness because it can lead to inaccurate diagnosis, tied in with this is also the challenge that 70% of the members of the DSM-5 committee have links to pharmaceutical companies (Psychology review 2014) therefore representing the view that people suffering from mental illnesses are best treated via medication.
No comments:
Post a Comment