Clasification And Diagnosis Flashcards
(33 cards)
what are positive symptoms?
those that are added to everyday experiences
what are negative symptoms?
they involve the loss of everyday functioning
what is a delusion?
bizarre beliefs that seem real but aren’t
what is an experience of control?
the person believes they are under control of an alien force that has invaded their mind.
what is an hallucination?
bizarre, unreal perceptions of the environment that are usually auditory
what is disordered thinking?
the feeling that thoughts have been inserted or withdrawn from the mind
what are the 4 examples of positive symptoms?
delusions
hallucination
disordered thinking
experience of control
what are the 3 examples of negative symptoms?
affective flattening
alogia
avolition
what is affective flattening?
a reduction in the range and intensity of emotional expression
what is alogia?
poverty of speech, characterised by the lessening of speech fluency and productivity.
what is avolition?
the reduction of, or inability to initiate goal-directed behaviour
what is chronic onset schizophrenia?
an insidious change in someone who gradually loses drive and motivation and slowly begins drifting from friends
what is acute onset schizophrenia?
obvious signs appear e.g. hallucinations suddenly usually after a stressful event. Shows disturbed behaviour within a few days.
what is reliability?
the consistency of the measuring instrument
what is inter-rater reliability?
when more than one experimenter gives the same results
ISSUES OF RELIABILITY:
The DSM-III has been updated to have inter-rater reliability, however, what have studies shown?
they found correlations as low as +11 with the diagnosis of schizophrenia so showing low reliability.
ISSUES OF RELIABILITY:
Study by Rosenhan
this included ‘normal’ people presenting themselves with hearing voices in their heads. They were all diagnosed as having schizophrenia and admitted. Throughout the stay, none of the staff realised they were actually normal. Showing the classification and diagnosis system needs to be altered because simply just claiming to hear voices is not evidence enough.
In a further study, he warned hospitals of his ‘normal’ patients and this resulted in a 21% detection rate. Showing more reliable but still issues.
ISSUES OF RELIABILITY:
Bizarre and non-bizarre delusions
For a diagnosis of schizophrenia, only one of the characteristic symptoms are required. 50 psychiatrists were asked to differentiate between bizarre and non-bizarre delusions. They produced inter-rater reliability of +40. Meaning the central diagnosis requirement (bizarre delusions) lacks reliability and so cannot be a sufficient method of diagnosing schizophrenia.
ISSUES OF RELIABILITY:
Schizophrenia was more commonly diagnosed with the ICD-10. why is this?
This could be due to the ICD putting more emphasis on the first rank symptoms where as the DSM emphasises the cause of the disorder and the functional impairment with it.
what is test-retest reliability?
the consistency over time
is the test-retest reliability high or low? how do we know this?
high with .84. Wilkes administered 2 forms of the test to schizophrenics and found this.
ISSUES OF RELIABILITY:
Cultural differences
They gave psychiatrists a description of a patient. 69% of the US psychiatrists diagnosed them as being schizophrenic compared to 2% of the British, suggesting the diagnosis lacks validity.
ISSUES OF VALIDITY:
what is validity?
the extent you measure what you intend to measure
ISSUES OF VALIDITY:
what is comorbidity
this refers to the extent that 2 or more conditions co-occur e.g. depression and schizophrenia.