Issues surrounding the Classification/Diagnosis of SZ

Question 1

two issues with the classification/diagnosis of SZ

Answer 1

• issues with validity
• issues with reliability

Question 2

validity

Answer 2

Validity =
• extent to which a diagnosis of SZ represents an accurate and real diagnosis that is distinct from other disorders
• extent to which a classification system such as the ICD or DSM measures what it intends to measure

Number of issues make it difficult for a classification system/diagnosis to be valid.

Question 3

issues with validity

Answer 3

• gender bias
• symptom overlap
• comorbidity

Question 4

issues with validity:
gender bias

Answer 4

Gender bias is said to occur when the accuracy of a diagnosis of SZ is dependent on the gender of an individual.

Eg, diagnostic criteria may be biased towards one gender.

Equally, clinicians may base their judgements on stereotypical beliefs held about gender.

Question 5

issues with validity:
symptom overlap

Answer 5

Some symptoms of SZ are also found in other disorders eg. depression and bipolar disorder (‘symptom overlap’).

Eg, both SZ and bipolar disorder involve positive symptoms like delusions and negative symptoms like avolition.

Makes it very difficult to accurately distinguish SZ from related disorders during diagnosis.

Also has similar symptoms to OCD, phobias, anxiety, dementia

Question 6

issues with validity:
comorbidity

Answer 6

Comorbidity = extent to which two (or more) conditions co-occur.

Eg. many people diagnosed with SZ may also suffer from depression, anxiety or substance abuse.

Creates difficulties, in being able separate out different conditions during diagnosis as well as deciding what treatments to advise.

Question 7

evaluation of issues with validity: STRENGTHS

Answer 7

P) evidence for gender bias from Loring and Powell
E) gc of randomly selected male/female psychiatrists given a case described as ‘male’ (56% diagnosed with SZ) or ‘female’ (20% diagnosed with SZ)
E) gender bias not as evident among the female psychiatrists
L) diagnosis lacks validity as it is subjective based on gender stereotypes, not just the facts of the case (symptoms)

P) evidence for symptom overlap from Ellason and Ross
E) pointed out: not only is there a great deal of overlap between SZ and bipolar disorder, but people with another disorder called ‘Dissociative Identity Disorder’ (DID) have more symptoms of SZ than people diagnosed with SZ
L) brings into question whether SZ, bipolar disorder and DID are separate disorders or part of the same spectrum.

P) evidence for comorbidity from Buckley et al (2009)
E) found comorbid depression occurs in 50% of SZ patients and 47% have a diagnosis of comorbid substance abuse.
E) suggests significant overlap between disorders
L) makes the diagnosis of schizophrenia as a distinct disorder very difficult

Question 8

reliability

Answer 8

Also issues with the reliability (or consistency) of SZ diagnosis.

Reliability can be measured in terms of:
• whether two independent assessors using the same classification system give the same diagnosis (inter-observer reliability)
• whether diagnostic tests are consistent on different occasions (test retest reliability)

Question 9

issue with reliability

Answer 9

culture bias

Question 10

issue with reliability (+ validity):
culture bias

Answer 10

Culture bias may lead to problems with both the reliability and validity of diagnosis.

Culture bias = when psychiatrists are influenced by their own culture’s values and expectations when diagnosing patients.

If what is seen as bizarre in one culture is not viewed as bizarre in another, this could lead to inconsistent diagnosis.

Question 11

evaluation of issues with reliability: STRENGTHS

Answer 11

P) evidence for lack of inter-observer reliability in diagnosis comes from Copeland (1971)
E) when British and American psychiatrists were given a description of a patient and asked for a diagnosis, 69% Americans diagnosed SZ, 2% British did
L) suggests diagnosis has very low inter-observer reliability between cultures

P) the fact patients from certain cultural groups are more likely to be diagnosed with SZ than others might suggest validity issues too
E) Harrison et al (1997): African-Caribbean groups were 8 times more likely to be diagnosed with SZ than white groups in the UK
E) suggests psychiatrists may be misinterpreting cultural differences in behaviour as ‘bizarre’ and therefore as symptoms when they are simply differences
L) such ethnocentric bias would reduce the validity of diagnosis.
E) BUT, it is possible that there are genuine differences between cultural groups caused by different experiences or genetic inheritance of SZ (eg. represent effects of the poorer housing, higher rates of unemployment and social isolation that are more commonly experienced by minority groups such as African-Caribbean groups)

Question 12

evaluation of issues with classification/diagnosis: GENERAL

Answer 12

P) major issue with invalid or unreliable diagnosis of SZ is the social stigma carried by being incorrectly labelled
E) eg struggle to find employment
L) inaccurate diagnosis can have a long-lasting negative impact on the lives of those diagnosed

P) Despite these problems, the classification systems allow professionals to share a common language
E) helps in communicating ideas and allows greater opportunities for research
E) eg while interpretation of symptoms may differ, the criteria remains consistent
L) lead to a better understanding of SZ