Reliability and validity in the diagnosis and classification of schizophrenia

Question 1

what does reliability refer to

Answer 1

consistency

Question 2

if a diagnosis is reliable what does this mean

Answer 2

it is consistent over time and by different psychiatrists

Question 3

what is inter-rater reliability

Answer 3

when two independent psychiatrists agree on a diagnosis of schizophrenia

Question 4

what is test-retest reliability

Answer 4

when the same person gives the same diagnosis using the same criteria on two separate occasions

Question 5

what is validity

Answer 5

the extent to which we are measuring what we intended to measure

Question 6

how can you assess the validity of a diagnosis of schizophrenia

Answer 6

criterion validity

Question 7

what is criterion validity

Answer 7

using two different measures and seeing if they arrive at the same diagnosis of schizophrenia

Question 8

what are the two diagnostic systems

Answer 8

ICD and DSM

Question 9

what does ICD stand for

Answer 9

international classification of diseases and related health problems

Question 10

what does DSM stand for

Answer 10

Diagnostic and statistical manual of mental disorders

Question 11

to be diagnosed with schizophrenia what does the DSM say you have to have to be diagnosed with schizophrenia

Answer 11

two or more symptoms for at least one month

Question 12

to be diagnosed with schizophrenia what does the ICD say you have to have to be diagnosed with schizophrenia

Answer 12

one very clear symptom

Question 13

what is a key difference between the DSM and the ICD

Answer 13

two negative symptoms are sufficient under the ICD

Question 14

why does the reliability and validity of diagnosing schizophrenia matter

Answer 14

misdiagnosis-people might be diagnosed with schizophrenia when they don’t have it
people that do have schizophrenia might be misdiagnosed as not having schizophrenia when they do
this is bad because antipsychotic drugs have strong side effects. That could negatively effect mental health in people who are inappropriately given these drugs

Question 15

what are the two research evidence points for whether schizophrenia diagnosis and classification is NOT reliable or valid

Answer 15

Rosenhan-pseudopatients
Cheniaux et al-two psychiatrist

Question 16

explain Rosenhan’s study

Answer 16

pseudopatients where presented to 12 different psychiatric institutionswith a single symptom of hearing a voice saying ‘hollow, empty, thud’ once admitted they behaved normally. all but one of the patients were given the label of paranoid schizophrenia with the other patient being labelled at bipolar
they then did a follow up study and said to institutes he would send them more pseudopatients. after three months they were confident about a third of new patients sent were pseudopatients when none had actually been sent

Question 17

how does Rosenhan not support the reliability or validity of the diagnosis and classification of schizophrenia

Answer 17

Reliability: the diagnosis was not consistent one was diagnosed with bipolar despite displaying identical symptoms
Validity: psychiatrists were not able to tell the difference between real and fake patients - they misdiagnosed healthy people as having schizophrenia and diagnosed mentally ill patients as healthy

Question 18

explain Cheniaux et al’s study

Answer 18

two psychiatrists independently diagnosed 100 patients using the DSM and ICD. one psychiatrist diagnosed 26 with schizophrenia using the DSM and 44 according to the ICD the other diagnosed 13 as having schizophrenia using the DSM and 24 with the ICD. The psychiatrists interpreted the criteria differently

Question 19

how does Cheniaux et al not support the reliability or validity of the diagnosis and classification of schizophrenia

Answer 19

reliability: poor inter-rater reliability
validity: suggests the correct diagnosis is not always given. Either DSM is underdiagnosing or ICD is over diagnosing

Question 20

what causes problems with diagnosis

Answer 20

comorbidity
symptom overlap
gender bias
cultural bias

Question 21

explain comorbidity

Answer 21

schizophrenia is commonly diagnosed alongside other conditions
50% of schizophrenic patients also have depression
47% have substance abuse
29% have PSTD
23% have OCD

Question 22

why does comorbidity make the diagnosis of schizophrenia less valid and reliable

Answer 22

reliability: different psychiatrists may not agree on what the primary diagnosis should be
Validity: schizophrenia may be missed and diagnosed as a more common disorder

Question 23

why does comorbidity have challenges on treatment

Answer 23

treatments for different disorders may counteract each other. need to decide what disorders to prioritise for treatment

Question 24

what is symptom overlap

Answer 24

overlap between symptoms of other conditions and schizophrenia
schizophrenia and bipolar both have symptoms of avolition and delusions

Question 25

why does symptom overlap make the diagnosis and classification less valid and reliable

Answer 25

Reliability: psychiatrists may not agree Validity: incorrect diagnosis might be given

Question 26

what is gender bias in diagnosis of schizophrenia

Answer 26

men are more likely to receive diagnosis of schizophrenia than women this is because men are more genetically vulnerable than women Women with schizophrenia tend to function better more likely to work and maintain good family relationships and tis could lead to women being underdiagnosed

Question 27

why does gender bias consequences matter

Answer 27

women who are misdiagnosed will receive the wrong treatment the more women underdiagnosed the greater the gender difference in schizophrenia will be, leading to more women being misdiagnosed

Question 28

what did Cotton find relating to gender bias

Answer 28

women with schizophrenia tended to report more mood symptoms than men, this means they are more likely to be diagnosed with depression or bipolar disorder

Question 29

what is cultural bias in the diagnosis of schizophrenia

Answer 29

people of Afro-Caribbean origin are significantly more likely to be diagnosed with schizophrenia it is not due to a genetic vulnerability because the rates of schizophrenia in Africa and Caribbean are not any higher in Europe therefore it must be cultural bias hearing voices is acceptable in African cultures because of cultural beliefs and communication with ancestors

Question 30

what did Kim and Berrios find relating to cultural bias

Answer 30

in Japan the thought of disorganised mind is so stigmatising that psychiatrists are reluctant to diagnose patients with schizophrenia. As a result only 20% of Japanese people with schizophrenia are aware of it