Schizophrenia: Classification and Symptoms

Question 1

What is the difference between positive and negative symptoms?

Answer 1

Positive: appear to reflect an excess or distortion of normal functions

Negative: reflect a loss of normal functions

Question 2

Name 2 positive and 2 negative symptoms

Answer 2

Positive: hallucinations/delusions

Negative: avolition (reduction of goal orientated behaviour)/ affective flattening (reduction in range and intensity of emotional expression)

Question 3

What are the two means of testing reliability?

Answer 3

1) inter-rater reliability

2) test-retest reliability

Question 4

Explain inter-rater reliability

Answer 4

Agreement of diagnosis between assessors.

The DSM-III was published in 1980; a reliable classification system for greater agreement of SZ diagnosis between psychiatrists.

Question 5

Explain test-retest reliability

Answer 5

Whether tests to measure SZ are consistent over time.

Question 6

Who tested the test-retest reliability?

Answer 6

Wilks et al (2003)

Question 7

What did wilks et al (2003) do/find studying test-retest reliability?

Answer 7

Administered two forms of cognitive screening tests to SZ patients over intervals varying between 1-134 days.

Test-retest reliability correlation was high at .84.

Question 8

What does validity refer to in SZ diagnosis?

Answer 8

The extent that a diagnosis represents something real and distinct from other disorders and extent to which classification systems measure what they claim to measure.

Question 9

What is comorbidity?

Answer 9

Refers to extent that two or more conditions co-occur. Psychiatric comorbidities are common in SZ patients.

Question 10

What comorbidities commonly occur alongside SZ?

Answer 10

Substance abuse
Anxiety
Depression

Question 11

Who studied comorbidity in SZ patients?

Answer 11

Buckley et al (2009)

Question 12

What did Buckley et al (2009) estimate about comorbidity in SZ patients?

Answer 12

Comorbid depression occurs in 50% patients.

Comorbidity of substance abuse occurs in 47% patients.

Question 13

What difficulties does comorbidity in SZ patients arise?

Answer 13

Difficulty in the diagnosis of disorder and deciding what treatment to advise.

Question 14

Who studied the validity of positive/negative symptoms for SZ diagnosis?

Answer 14

Klosterkotter et al (1994)

Question 15

What did Klosterkotter et al (1994) find about the validity of positive/negative symptoms for SZ diagnosis?

(Who did they assess?)

Answer 15

Assessed 489 admissions to psychiatric unit in Germany.

Found that positive symptoms were more useful for diagnosis.

Question 16

Define prognosis

Answer 16

Medical term for predicting a likely outcome.

Question 17

Why is prognosis difficult with SZ patients?

Answer 17

SZ patients rarely share the same symptoms or outcomes.

Question 18

Who studied prognosis for SZ patients?

What statistics did they find about SZ outcomes?

Answer 18

Bentall et al (1998)

20% recover to previous level of functioning

10% achieving significant improvement

30% showed improvement with relapse

Question 19

What does difficulty with prognosis mean for issues of validity?

Answer 19

Diagnosis of SZ has little predictive validity.

Question 20

Evaluation: ☹️

Who found that the inter-rater reliability correlations for DSM-lll were as low as .11?

Answer 20

Whaley (2001)

Question 21

Evaluation: ☹️

What is the only characteristic symptom needed for SZ diagnosis?

Why is this a problem for reliability?

Answer 21

‘If delusions are bizarre’

This definition is not specific; v subjective.

Question 22

Evaluation: ☹️

Who studied unreliable symptoms for diagnosis reliability?

Answer 22

Mojtabi and Nicholson (1995)

Question 23

Evaluation: ☹️

What did Mojtabi and Nicholson (2003) do/find studying unreliable symptoms in the US?

Answer 23

Asked 50 senior psychiatrists to differentiate between ‘bizarre’ and ‘non-bizarre’ delusions.

Produced inter-rater reliability correlations of only +.40.

Question 24

Evaluation: 😊

Who analysed test-retest reliability by studying several measures of attention and info processing?

Who did they study and what were the results?

Answer 24

Prescott et al (1986)

Studied 14 chronic SZ patients.

Found test-retest reliability stable over 6 month period.

Question 25

Evaluation: ☹️ Who conducted the experiment 'On Being Sane in Insane Places'?

Answer 25

Rosenhan (1973)

Question 26

Evaluation: ☹️ Explain Rosenhan's study (low reliability of diagnosis)

Answer 26

Normal people presented themselves to US psychiatric hospitals claiming they heard unfamiliar voices saying the words 'empty', 'hollow' and 'thud'. They were all diagnosed with SZ and admitted. Throughout their stay, none of the staff recognised that they were pseudo patients.

Question 27

Evaluation: ☹️ Describe Rosenhan's follow up study

Answer 27

Rosenhan warned hospitals of his intentions to send out more 'pseudo patients'. This resulted in a 21% detection rate- even though he never sent any!

Question 28

Evaluation: 😊 Comorbidity: what comorbid condition increases the risk for suicide?

Answer 28

Depression

Question 29

Evaluation: 😊 Comorbidity: who studied comorbid suicide rates? What did they find?

Answer 29

Kessler et al (1994) Rate for attempted suicide rose from 1% for those with SZ alone to 40% with at least one comorbid mood disorder.

Question 30

Evaluation: ☹️ Symptoms: why might the identification of symptoms not always make SZ diagnosis highly valid?

Answer 30

The symptoms are also found in many other disorders, such as bipolar disorder and depression.

Question 31

Evaluation: ☹️ Who pointed out that people with dissociative identity disorder (DID) actually have more schizophrenic symptoms than people diagnosed with SZ?

Answer 31

Ellason and Ross (1995)

Question 32

Evaluation: ☹️ Who studied cultural differences in diagnosis? (Reliability)

Answer 32

Copland (1971)

Question 33

Evaluation: ☹️ What did Copeland (1971) do/find studying cultural differences in diagnosis?

Answer 33

Gave 134 US and 194 British psychiatrists a description of a patient. 69% of US psychiatrists diagnosed SZ but only 2% of British psychiatrists gave same diagnosis.