Rel/val Of DSM Flashcards
Beck
Low reliability
Early versions of the DSM were not reliable agreement on diagnosis of 153 patients was only 54% due to vague criteria and inconsistency in the techniques used to gather data.
Cooper
Low reliability
Early versions of the DSM were not reliable New York psychiatrists were twice as slightly to diagnose someone with schizophrenia then London psychiatrist who was twice as slightly to diagnose depression when they were shown the same videotape of clinical interviews
Di Nardo
Low reliability
Studied the reliability of the DSM III for anxiety disorders. Two clinicians separately diagnosed 267 people using kappa statistics found low reliability for GAD due to problems interpreting excessive worries DSM IV corrected this.
High reliability
High reliability was found for OCD
Rosenhan
High reliability
Early versions of the DSM could be reliable as 7 out of 8 pseudo patients were diagnosed with schizophrenia and only one with manic psychosis
Low validity
Psychiatrists were fooled by patients faking a single symptom of schizophrenia
Goldstein
High reliability
looked at the effect of gender on schizophrenia 199 patients were rediagnosed with the DSM III and a few differences were found because of the updated system.However, patients were blindly rediagnosed by three clinicians and high inter reliability was found.
Conclusion of reliability
We can conclude that the reliability of classification systems have improved overtime because of the major following changes
A multi axle approach
More standardised assessment techniques
More specific criteria
What is predictive validity
When a diagnostic system identifies as a condition that will respond a particular way to a treatment.
what is criterion validity
When our diagnostic system diagnosis agrees with a diagnosis made a different way
What is construct validity?
Extent to which category of mental disorder really exists this might be called to question if symptoms are very similar to those of another condition or if two conditions occur regularly together
Allardyce
Low validity
Problems with construct validity of schizophrenia. hallucinations are bizarre experiences, but there is no cut-off point where a daydream turns into SZ. SZ has a large range of symptoms the patient with the same diagnosis may appear different to each other and many SZ symptoms over lap with other mental disorders SZ patient may appear more similar to someone with a different diagnosis. it is unclear whether patient suffering from predominantly negative symptoms have the same condition as those suffering from mostly positive symptoms.
Hoffmann
High validity
Looked at different diagnosis of alcohol abuse/dependence and cocaine independence to see if a difference would show in a structured computer prompted interview it was found DSM diagnosis was valid and the illness corresponded to the DSM criteria
Sanchez-villages
High validity
Standardised interview from DSM IV to 62 participants with depression and 42 without depression 68% work were correctly identified as depressed and 81% of the 42 were confirmed as not depressed . Those who were diagnosed with depression my had picked it up recently before the interview shows how hard it is to establish validity.
Overall conclusion
We can conclude the validity of classification systems have improved overtime but there are still problems with the line between normal and abnormal and cultural differences
