Classification and Diagnosis Issues

Question 1

Kleitman’s 3 factors affecting the reliability of diagnosis

Answer 1

Difference: in procedures (classification systems), between clinicians (subjective interpretation), between patients

Question 2

Improvements of reliability over time: DSM 2

Cause of low reliability, 2 studies

Answer 2

Vague
Beck 1967: 54% inter-rate reliability
Cooper 1972: low agreement between US and Britain

Question 3

Improvement of reliability over time: DSM 3

What year? 1 study?

Answer 3

1980

American Psychiatric Association (APA) = 81% consistent diagnosis

Question 4

Improvements of reliability over time: DSM 4

1 study? Sub-types of schizophrenia?

Answer 4

Cheniaux (2009): kappa statisics 0.59 DSM 4, 0.61 between DSM 4 and ICD 10

Question 5

Improvements of reliability over time: DSM 5

APA finding? Comparison to other conditions?

Answer 5

APA: kappa = 0.46 (lower but used real-life setting)

alcoholism, binge eating and bipolar = similar stats. PTSD, autism and ADHD = higher

Question 6

What is reliability? What is validity?

Answer 6

Consistency

Truth

Question 7

What does the validity of a diagnosis rely on? (2) What affects these two things?

Answer 7

reliability of diagnosis and validity of classification

reliability of classification

Question 8

What is the normal inter-rater reliability we would expect?

Study on this?

Answer 8

0.7 agrrement

Mojtabi and Nicholson 1995: 0.4 between clinicians on whether hallucinations were ‘bizarre’

Question 9

Why would patients present differently? (2)

Answer 9

Their mood and the variability of their symptoms

Question 10

Why would patients present differently to different doctors? (3)

Answer 10

Demographic of the doctor (gender/age/ethnicity), personality (warmth) and skill in questioning

Question 11

Define descriptive validity

Answer 11

The symptoms make the condition clearly distinguishable from other conditions

Question 12

Define aetiological validity

Answer 12

The causes or mechanisms of the condition is clear

Question 13

Define predictive validity

Answer 13

For a well defined illness, the progression is known and reaction to treatment can be predicted

Question 14

Which is more likely to produce a Type 1 or 2 error: DSM or ICD?

Answer 14

ICD: Type 1 (false positive) more likely as symptoms don’t have to have been present for more than 1 month, DSM more likely type 2 error (false negative)

Question 15

What is cluster analysis?

Answer 15

Investigates whether symptoms of an illness co occur (if having one symptom is associated with having others) If you have one symptom of schizophrenia you should be more likely to have the other symptoms than other people

Question 16

Who conducted cluster analysis in schizophrenia?

Answer 16

Liddle: 3 clusters of symptoms: positive, negative and symptoms of cognitive disorganisation

Question 17

What issue does schizophrenia have with descriptive validity?

Answer 17

schizophrenia and depression often blurred because they share negative symptoms, suggests 2 disorders are not clearly distinguished enough

Question 18

What research seems to prove that schizophrenia has aetiological validity?

Answer 18

Howes and Kapur 2008: pre-synaptic dysregulation of dopamine is involved in all cases of schizophrenia that have psychotic symptoms, this is the common mechanism, initial cause of dysregulation may be different

Question 19

What would increase aetiological validity in schizophrenia?

Answer 19

redefine schizophrenia based on the 3 clusters -single mechanism for each cluster

Question 20

What would increase aetiological validity in schizophrenia?

Answer 20

redefine schizophrenia based on the 3 clusters -single mechanism for each cluster

Question 21

What feature of schizophrenia reduces its predictive validity?

Answer 21

variability in prognosis: 1/3 patients remain chronically ill, 1/3 recover from initial illness, 1/3 have period of illness and periods of being well

Question 22

What id difficult to predict for schizophrenic patients?

Answer 22

How they will respond to drug treatment, all drugs that have any effectiveness affect dopamine receptors, some drugs also affect serotonin receptors

Question 23

Which psychologist documented a case study of the consequences of false positives?

Answer 23

Swartz 2001: 46yrs women, treating as having schizophrenia for 10yrs, EEG revealed epilepsy though she had had treatment with antipsychotics, most appropriate treatment withheld for 10yrs

Question 24

What research shows the effect of false-positive schizophrenia diagnosis on those with Asperger syndrome?

Answer 24

Perlman 2000: cases of chronic undifferentiated schizophrenia but didn’t fit criteria right, unnecessary antipsychotics without any positive symptoms, actually has Asperger syndrome

Question 25

What are the other affects of a false positive diagnosis?

Answer 25

the label schizophrenia may become part of identity, in self-fulfilling prophecy may start to demonstrate symptoms which reinforces the diagnosis

Question 26

What were the findings of Rosenhan’s 1973 study?

Answer 26

The fake schizophrenic patients behaviour was all interpreted based on their original diagnosis: making notes = writing behaviour which was considered abnormal, arriving early for lunch = oral inquisitive

Question 27

What are the consequences of a false negative diagnosis?

Answer 27

schizophrenics not given treatment so left t deal with their illness, symptoms worsen, no support, vulnerability