Issues with the classification of schizophrenia including reliability and validity

Question 1

Define reliability.

Answer 1

Reliability is the extent to which psychiatrists can agree on the same diagnoses when independently assessing patients.

Question 2

What are the two types of diagnostic tools?

Answer 2

In the UK we use the DSM diagnostic tool however other parts of the world may use the ICD tool to diagnose Schizophrenia.

Question 3

Outline the issue of reliability with the diagnostic tools.

Answer 3

Issues with reliability first arise as both these tools have different diagnostic criteria’s; for example the DSM tool recognizes 5 subtypes of Schizophrenia while the ICD tool recognizes 7 subtypes. This means diagnosis is not consistent between different parts of the world dependent on the tool being used - this means one country may diagnose someone as normal while another place with the same symptoms may see them as Schizophrenic. Therefore there is a clear cultural bias dependent on which identification tool is being used and where the individual is in the world highlighting how inconsistent diagnosis actually is.

Question 4

Why is there a problem with validity and what consequences does it have?

Answer 4

Schizophrenia is evidently not understood well enough to diagnose accurately. This has huge consequences for those diagnosed as this can lead to them being stigmatised and mistreated raising ethical concerns.

Question 5

Outline another ethical concern with the classification of schizophrenia.

Answer 5

A person can also only ever be classed as a Schizophrenic in remission and not cured meaning such a label may stay with them affecting other areas of life (Employment, social interaction with people and how they are perceived) raising further ethical issues.

Question 6

What makes objective diagnosis so difficult?

Answer 6

There is also no physical cause that can be conclusively measured for Schizophrenia and a great deal of emphasis is placed on the patients ability to report the symptoms which may not always be accurately described (possible due to schizophrenia) further hindering reliability of diagnosis. Relying on patients reporting symptoms therefore makes objective diagnosis difficult.

Question 7

Another issue which makes the diagnosis less reliable and objective?

Answer 7

Also interpretation of symptoms is subjective and down to the person doing the diagnosis so a great deal of importance is placed on the individual’s ability in diagnosis which may vary between health professionals. Therefore skill, experience and knowledge further affect reliable diagnosis.

Question 8

What did Whaley et al. find?

Answer 8

Whaley et al found Inter-rater reliability between health professionals as low as 0.11. in diagnosis. This means when independently assessing patients, the diagnosis was rarely consistent between them meaning the DSM tool appears to be unreliable in accurately and consistently diagnosing Schizophrenia.

Question 9

What did Mojtabi find?

Answer 9

Mojtabi found; When 50 senior psychiatrists in the US were asked to differentiate between “bizarre” and “non-bizarre” delusions, they produced inter-rater reliability correlations of only 0.40 suggesting even this diagnostic requirement lacks sufficient reliability to distinguish between schizophrenic and non-schizophrenic symptoms. Therefore attempting to use “bizzare” as a means to diagnose schizophrenia is reductionist and simply an attempt to overs-simplify
something we do not fully understand.

Question 10

Outline Rosanhans main study.

Answer 10

Rosanhans famous study highlighted the unreliability of diagnosis for Schizophrenia further. Normal people presented themselves to psychiatric hospitals in the US claiming to hear voices. They were all diagnosed as having Schizophrenia and admitted. Throughout their stay none of the hospital staff recognized they were actually normal highlighting the unreliability of diagnosis for Schizophrenia raising serious ethical issues.

Question 11

Explain Rosanhans follow up study.

Answer 11

In a follow up study Rosanhan called hospitals informing them he would be sending in “fake patients” however none were really sent. This resulted in an apparent 21% detection rate. This further highlights how diagnosis methods are unreliable meaning current understanding of Schizophrenia is insufficient and lacking validity.

Question 12

What are the consequences of Rosanhan’s studies?

Answer 12

Reliability and Validity are linked together and if health practitioners cannot conclusively agree who has Schizophrenia, this raises the question of what it actually is (Validity) and whether our understanding of it is sufficient.

Question 13

What did Bentall conclude?

Answer 13

Bentall et al conducted a comprehensive review of research into the symptoms, causes and outcomes of Schizophrenia and concluded that Schizophrenia was not a useful scientific category.

Question 14

What did Schneider develop?

Answer 14

Schneider developed the First Rank symptoms that he believed distinguished Schizophrenia from other disorders e.g. delusions of being controlled, the belief that thoughts are being broadcast, hearing hallucinatory voices. The belief was that the existence of these first rank systems would make diagnosis
more reliable and thus more valid.

Question 15

Issues with Schneider’s symptoms?

Answer 15

Issues with validity arise as such symptoms overlap with other disorders such as depression and bipolar disorder. Ellason & Ross point out that people with dissociative Identity disorder (DID) actually have more Schizophrenic symptoms than people diagnosed with it.

Question 16

Implications of Ellason & Ross’ study?

Answer 16

This raises issues of Comobidity as symptoms may appear to fit in with Schizophrenia however may be due to a combination of other illnesses that resemble it making diagnosis unreliable and treatment difficult. If we do not accurately know what Schizophrenia is we cannot sufficiently treat it.

Question 17

Research on recovery?

Answer 17

Research suggests that the outcomes for patients diagnosed with Schizophrenia varies with only 20% recovering their previous level of functioning, 10% achieving significant and lasting improvement and 30% showing some improvement with intermittent relapses.

Question 18

Why does diagnosis of Schizophrenia has little predictive validity?

Answer 18

A diagnosis of Schizophrenia therefore has little Predictive validity as some people never appear to recover from the disorder while others may do. We cannot fully understand why this is and this highlights exactly how reductionist our tools in identification are as we clearly do not understand the disorder or why it varies from one individual to another.

Question 19

Further issues which make the diagnosis and treatment difficult?

Answer 19

Further issues arise as we are still unclear as to what causes the disorder and various explanations exist meaning classification; diagnosis and even treatment all become difficult. Explanations vary from biological to psychological and without knowing what causes it; it is difficult to fully classify what we are dealing with and treating it.

Question 20

Outline Copeland’s research.

Answer 20

Copeland et al highlighted cultural differences in diagnosis and how this varies greatly between countries. Giving a description of a patient to US psychiatrists and British Psychiatrists; 69% of those from the US diagnoses the patient with Schizophrenia while only 2% of British psychiatrists did. Therefore differences exist in what people expect symptoms to look like and this creates highlights further issues in diagnosis and cultural bias as behaviour in one country may be seen as relatively normal within the context of that culture but possibly a symptom of schizophrenia in another country/culture.