Reliability and validity in diagnosis and classification of schizophrenia

Question 1

Outline

Answer 1

Reliability and validity are linked together as if the diagnosis of psychiatrists is not reliable (not consistent) then it will not be valid (accurate) either as they clearly do not know what they are looking for.

Question 2

Rosenhan’s (1973) ‘being sane in insane places’ shows poor validity of diagnosis

Answer 2

The fact that he got normal people to pretend to be insane & all of them got into different mental institutions suggests that psychiatrists were poor at diagnosing schizophrenia accurately. (institutions also claimed they found more fake patients following the study when no more were sent by the researchers)

Question 3

Rosenhan’s (1973) ‘being sane in insane places shows poor reliability of diagnosis

Answer 3

as not all the pseudo-patients (fakers) were given the same diagnosis when they presented themselves to psychiatric hospitals in the US despite the fact that they all presented the same symptom of hearing unfamiliar voices that said ‘empty’, ‘hollow’ and ‘thud’

Question 4

Cheniaux et al (2009) supports poor reliability in diagnosis

Answer 4

who had two psychiatrists independently diagnose 100 patients using both DSM and ICD criteria and found poor inter-rater reliability.

Question 5

Co-morbidity

Answer 5

relates to two or more conditions occurring together. Schizophrenia is commonly diagnosed with other conditions. Buckley et al (2008) concluded that around half of schizophrenic patients also had a diagnosis of depression. (could be misdiagnosed)

Question 6

Symptom overlap

Answer 6

there is considerable overlap between the symptoms of schizophrenia and other conditions. E.G. bipolar disorder also involves positive symptoms like delusions and negative like avolition. (could be one condition)

Question 7

Gender bias in diagnosis

Answer 7

Longnecker et al (2010) found that since the 1980s men have been diagnosed with schizophrenia rather more often than women.

Question 8

Cultural bias in diagnosis

Answer 8

African Americans and English of Afro-Caribbean origin are far more likely than white people to be diagnosed. This could be because positive symptoms like hearing voices are more acceptable in African cultures.