Classification + Diagnosis

Question 1

Positive symptoms

Answer 1

Those that appear to reflect an excess or distortion of normal functions

Delusions

Experiences of control

Hallucinations

Disordered thinking

Question 2

Negative symptoms

Answer 2

Those that appear to reflect a diminution or loss of normal of normal functions

Affective flattening

Avolition

Alogia

Question 3

Delusions

Answer 3

Bizarre beliefs that seem real to the person with sz but are not real e.g. inflated beliefs about the person’s power

Question 4

Experiences of control

Answer 4

Person may believe they are under control of an alien force that has invaded their mind

Question 5

Hallucinations

Answer 5

Bizarre, unreal perceptions of the environment that are usually auditory but may also be visual, olfactory or tactile

Question 6

Disordered thinking

Answer 6

Feeling that thoughts have been inserted or withdrawn from the mind

Person may believe their thoughts are being broadcasted, so others can hear

Question 7

Affective flattening

Answer 7

A reduction in the range + intensity of emotional expression, e.g. facial expression, voice tone eye contact + body language

Question 8

Avolition

Answer 8

Reduction or inability to initiate + persist in, goal-directed behaviour = often mistaken for apparent disinterest

Question 9

Alogia

Answer 9

Poverty of speech, characterised by lessening of speech fluency + productivity

Reflects slowing or blocked thoughts

Question 10

Reliability

Answer 10

Refers to consistency of a measuring instrument e.g. questionnaire or scale, to assess

Question 11

How can reliability be measured?

Answer 11

In terms of whether 2 independent assessors give similar diagnoses = inter-rater reliability

Or whether tests used to deliver these diagnoses are consistent over time = test-retest reliability

Question 12

Inter-rater reliability

Answer 12

DSM-III designed to provide a much more reliable system to classify disorders

Review: claimed DSM had fixed problem of inter-rater reliability once and for all

Now there was a reliable classification system = led to much greater agreement over who had Sz

Question 13

Test-retest reliability

Answer 13

Cog screening tests e.g. RBANS = important for diagnosis of Sz as they measure the degree of neuropsychological impairment

Wilks et al: gave 2 alternate forms of cog test to Sz patients over intervals varying from 1-134 days

Test-retest reliability was high at .84

Question 14

Validity

Answer 14

Refers to extent that a diagnosis represents something that is real + distinct from other disorders + the extent that classification system such as DSM measures what it claims to measure

Question 15

Comorbidity

Answer 15

Refers to the extent that two conditions co-occur

Psychiatric comorbidities are common among p’s with Sz e.g. substance abuse, anxiety + depression

Comorbidity creates difficulties in diagnosis of a disorder + deciding what treatment to advise

Question 16

Buckley et al

Answer 16

Estimated that comorbid depression occurs in 50% patients + 47% of patients also have lifetime diagnosis of comorbid substance abuse

Question 17

Positive or negative symptoms?

Answer 17

Found +ve symptoms were more useful in diagnosis than -ve symptoms

Question 18

Prognosis

Answer 18

Sz’s rarely share the same symptoms, no is there evidence that they share the same outcomes

Diagnosis had little predictive validity = some people never appear to recover but many do

Question 19

Evaluation of Inter-rater reliability

Answer 19

Still little evidence that DSM is used with high reliability by mental health clinicians

Whaley = Inter-rater reliability correlations in sz diagnosis as low as +.11

Question 20

Rosenhan

Answer 20

Normal people presented to psychiatric hospital in US claiming heard unfamiliar voice sating ‘empty’, ‘ hollow’ + ‘Thud’

ALL were diagnosed as Sz + admitted + staff didn’t recognise normality

Follow-up study = warned hospitals of pseudopatients = 21% detection rate despite none being there

Question 21

Unreliable symptoms

Answer 21

Onlt 1 characteristic of Sz needed if delusions are bizarre = what is bizarre?

Asked 50 US psychiatrists = inter-reliability correlations of only +.40

Question 22

Comorbidity + medical complications

Answer 22

Poor levels of functioning in Sz = result of untreated comorbid physical disorders than sz

P’s diagnosed with Sz also diagnosed with medical probs e.g diabetes or asthma

Consequence of being diagnosed with Sz = p’s tend of receive lower standard of medical care = adversely affects their prognosis

Question 23

Suicide risk

Answer 23

Sz’s pose high risk for suicide, which comorbid depression being major cause

Attempted suicide rate rose from 1% for those with only Sz to 40% for those with comorbid mood disorder

Question 24

Ethinicity

Answer 24

UK: rates of Sz = higher in African-caribbeans than white

Harrison et al = Sz incidence rate for Sz = 8 x higher for African-caribbean groups than white

Could be result of poor housing, higher rates of unemployment + social isolation

Or result of cultural factors: language + mannerisms

Question 25

Symptoms evaluation

Answer 25

Many symptoms of Sz are found in other disorders e.g. depression + bipolar

People with dissocitive identity disorder have more Sz symptoms than those diagnosed with Sz