Psya4 - P - Issues Surrounding The Classification And Diagnosis Of S., Including Reliability And Validity

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Issues surrounding the classification and diagnosis

Issues with the classificatory systems (DSM & ICD)

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+ Advantage of DSM/ICD is they aim to provide a more systematic approach in diagnosis and classification, producing a relaible and valid system and ultimately will allow us to develop more effective treatment programmes.


- Differences in different systems:
- Changes over time:

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Issues surrounding the classification and diagnosis
VALIDITY

Reliance on self-report

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- Due to there not being an objective diagnostic test for S, for a diagnosis to happen, the psychiatrist must rely partially on patient report. As S is a psychotic disorder and one of the ‘negative symptoms’ of S is poverty of speech, this may be hard for some of the patients to do.

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Issues surrounding the classification and diagnosis
VALIDITY

Reliance on observation in hospital environment

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Psychiatric observations are normally conducted in a hospital environment. Is excessive movement of a limb catatonic behaviour or a nervous response to a new scary situation? Rosenhan’s research was highly critical of psychiatric diagnosis, and one of his major criticisms was that once labelled as being ‘schizophrenic’ all of the behaviours demonstrated by the pseudo patients in the hospital were interpreted as evidence for their disorder when really it was just the reactive behaviours of bored individuals living in a psychiatric hospital.

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Issues surrounding the classification and diagnosis
RELIABLE BUT NOT VALID?

Reliance on observation in hospital environment

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However, what Rosenhan fails to highlight is that on all except one occasion, his pseudo patients were diagnosed with exactly the same condition on admission – surely this highlights how reliable these unsuspecting psychiatrists were in their diagnosis? Kety (1975) also reminds us in his ‘quart of blood’ scenario, that just because none of the psychiatrists detected that the pseudopatients were faking their initial symptom, it doesn’t mean that the psychiatrists wouldn’t be able to diagnose S if legitimate patients were in front of them. This reinforces the problem that diagnosing S isn’t based on an objective physiological test and hence is open to bias.

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Issues surrounding the classification and diagnosis
EXTERNAL RELIABILITY ISSUES

Differences in different diagnostic symptoms

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S is one of the few psychiatric conditions that is thought to exist in all cultures and yet there are still differences in the symptoms necessary for diagnosis.
UK Doctors use ICD whereas USA Doctors use DSM. ICD, one + symptom for one month to be diagnosed as having S.
DSMIV, two + symptoms for at least six months to be diagnosed.
Lack of consistency between diagnostic systems mean a person in the USA may not be diagnosed as having S whereas in UK they may be. Copeland found that 69% of US psychiatrists and only 2% of UK psychiatrists gave a diagnosis of S when given the same description of a patient. This suggests that the reliability of the different cultures’ classification systems is questionable.

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Issues surrounding the classification and diagnosis
VALIDITY

Variation in the symptoms of people with S.

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Lack of consistency of symptoms of different individuals given the diagnosis of S. This lack of homogeneity may lead not only to problems with diagnosis, but also the prognosis of S.
Bentall believed each S symptom should be treated as a different disorder. This highlights the issue that the classification of S may not only be invalid but is possibly a lot more complex than first thought.

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Issues surrounding the classification and diagnosis
VALIDITY

Comorbidity problems

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Buckley (2009) estimated that comorbid depression occurs in 50% of patients with S. Firstly, it means that it’s difficult to tell what is the primary disorder is, but secondly it is difficult to distinguish which disorder S or D might be causing which symptom. Symptoms of S might include hallucinations and delusions, however these are also the found in those with bipolar depression. This might suggest that the diagnosis is only certain and valid when only one disorder is present which means that co morbidity with S is potentially a big validity problem.

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Issues surrounding the classification and diagnosis
VALIDITY

Social class biases

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Traditionally, psychiatrists came from a restricted background, especially that of the white, upper-class. In Rosenhan’s research, the only pseudopatient admitted to a private hospital was the only one NOT to receive the diagnosis of S. Keith et al (1991) found that people from lower socioeconomic classes were more frequently diagnosed as suffering from S than those from higher classes, (1.9% compared to 0.4%. However is this really a bias in the diagnosis? Munk & Mortensen (1992) believed people who suffer from S exhibit a ‘downward drift’ in society. Although there may be class biases in psychiatric diagnosis, limiting their validity, the fact that there are also alternative explanations for these statistics suggests it might not be the only factor.

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Issues surrounding the classification and diagnosis
VALIDITY

Does S really exist or is it a method of social control?

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American Psychiatrist Szasz believed labelling someone as being ‘mentally ill’ was just a way of excluding non-conformists. This view may seem extreme, but in Soviet Russia when dissidents were caught distributing anti-government literature a psychiatrist would testify that the dissident is suffering from ‘sluggish schizophrenia’. The result of which is that the dissident is incarcerated in a maximum security hospital for an indefinite period. This example clearly demonstrates how the ‘establishment’ can bring the validity of diagnosing S into doubt.