Schizophrenia: Classification And Diagnosis Of Schizophrenia Flashcards
Name two issues of classification and diagnosis of Schizophrenia
> Reliability
> Validity
Name two measures of reliability
> Inter-rater Reliability
>Test-retest Reliability
Define Inter-rater reliability
This measures reliability of questionnaires or scales which assess the severity of schizophrenic symptoms, by seeing whether two independent assessor a give similar diagnoses.
Define test-retest reliability
This is a method used to check external reliability. The same test or interview is given o the same participants on two occasions to see if he same results are obtained
Name two types of validity
> Comorbidity
> Prognosis
Define Comorbidity
Comorbidity is the presence of two or more co-existing conditions or diseases. Such Comorbidity creates difficulties in the diagnosis of a disorder and also in deciding what treatment to advise
Define Prognosis
People diagnosed as schizophrenic rarely share the same symptoms, nor is there evidence that they share the same outcomes. A diagnosis of schizophrenia, therefore has little predictive value and some people never appear to recover from the disorder by end up doing so.
Evaluate inter-rater reliability
Despite the claims for increased reliability in DSM, over 30 years later there still little evidence that DSM is routinely used with high reliability by mental health clinicians.
Name a study which backs the evaluation of inter rater reliabiity
Whaley
What did Whaley find?
Whaley carried out a recent study which found that inter rater reliability correlations in the diagnosis of schizophrenia as low as +.11.
Evaluate Test-retest reliability
Measures of cognitive functioning are vital in the diagnosis of schizophrenia, therefore must have test-retest reliability to be useful in this role.
Name a study which supports the evaluation of test-retest reliability
Prescott et al.
What did Prescott et al. find?
Prescott et al. analysed the test retest of several measures of attention and information processing in 14 chronic schizophrenics. Performance on these measures was stable over a 6-month period.
Describe the issue of cultural differences in diagnosis
The reliability of diagnosis in schizophrenia is further challenged by the finding that there is massive variation between countries.
Name a study which supports cultural differences in diagnosis
Copeland
Describe Copeland’s findings
Copeland gave 134 US and 194 British psychiatrists a description of a patient. 69% of US psychiatrists diagnosed schizophrenia but only 2% of the British psychiatrists gave the same diagnosis.
Evaluate Comorbidity and suicide risk
Persons with schizophrenia pose a relatively high risk for suicide with comorbid depression being the major cause for suicidal behaviour.
Name a study which supports the evaluation of Comorbidity and suicide risk
Kessler et al.
Describe Kessler’s findings
Kessler et al. found that among patients in the National Comorbidity Survey the rate of attempted suicide rose from 1% for those with schizophrenia alone to 40% for those with at least one lifetime comorbid mood disorder.
