Classification Of Schizophrenia

Question 1

Reliability in schizophrenia diagnosis

Answer 1

Reliability is the level of agreement on a diagnosis by different clinicians (inter-rater), different cultures and different occasions (test -retest). For the classification system to be reliable for schizophrenia and other disorders, different clinicians should arrive at the same diagnosis for the same individual. This should occur despite any system differences (e.g use of DSM-V or ICD-10).

Question 2

validity

Answer 2

validity is the extent to which schizophrenia is a syndrome with unique characteristics and symptoms.

For the classification system to be valid, it should classify a pattern of symptoms which result from a real underlying cause.

Question 3

Rosenhan’s key study: (AO1 or AO3)

Answer 3

Study based on Elizabeth Cochrane who was admitted to a mental ward after faking symptoms of being insane, even though she was sane.
between 1969 and 1972 Professor Rosenhan sent eight pseudo-patients to 12 psychiatric hospitals without revealing this to the staff. None of the pseudo patients had any symptoms or history of mental disorders.
They arrived at the hospital and all faked one single symptom: hearing a voice saying “hollow, empty, thud” which didn’t represent any known symptom of schizophrenia.
All 12 pseudo patients were diagnosed with a mental disorder and hospitalised.
In a follow up study due to disagreement from the psychiatric hospital, Rosenhan was asked by them to send more pseudo patients, as they suggested that they’d be able to identify them. The psychiatric ward concluded that there were 41 pseudo patients sent over the time period of the study. No pseudo-patients were actually sent. These findings provided convincing evidence against the accuracy and validity of psychiatric diagnosis.

Question 4

DSM-V criterion for diagnosis

Answer 4

Two (or more) symptoms present for a significant portion of time during a 1 month period.

Question 5

ICD-10 criterion for diagnosis

Answer 5

At least one positive and one negative symptom must be present across a significant period of time.

Question 6

AO3 positives

Answer 6

+ Excellent reliability: diagnosis of schizophrenia has excellent reliability between clinicians (inter-rater) and between occasions (test-retest) This is due to the fact that a study reported DSM-5 inter-rater reliability of +97 and test-retest ability of +92. This means that the diagnosis can be consistently applied.

Question 7

AO3 negatives

Answer 7

• comorbidity: If conditions often co-occur then they might be a single condition. Sz is commonly diagnosed with other conditions. For example, Buckley et al (2009) concluded that Sz is co-morbid with depression (50% of cases), substance abuse (47%) or OCD (23%). This suggests that Sz may not exist as a distinct condition.
• symptom overlap: There is an overlap between the symptoms of Sz and other conditions e.g. both Sz and bipolar disorder involve delusions and avolition. Sz and bipolar disorder may be the same condition (a classification issue). Sz is hard to distinguish from bipolar disorder (a diagnosis issue). This means that Sz may not exist as a condition and, if it does, it is hard to diagnose.
• Some symptoms e.g. hearing voices, are accepted in some cultures, e.g. Afro-Caribbean societies ‘hear voices’ from ancestors. Afro-Caribbean British men are up to ten times more likely to receive a diagnosis as white British men, probably due to over interpretation of symptoms by UK psychiatrists. This means that Afro-Caribbean men living in the UK appear to be discriminated against by a culturally-biassed diagnostic system.