Schiz - Issues in diagnosis Flashcards
Two ways to measure reliability in diagnosis
Inter-rater reliability (observer reliability)
Test-retest reliability (external reliability)
Evaluating reliability- Copeland
P - IN EVALUATION, a study to highlight problems with inter-rater reliability of the diagnosis of schizophrenia, was conducted by Copeland (1970) which illustrates how the culture of the clinician can damage INTER-RATER reliability.
E - Copeland
L - This suggests…the reliability of diagnosing schizophrenia is influenced by location and culture of the clinician
What did Copeland do
Gave a description of a patient to 134 US and 194 British psychiatrists and found that 69% of the US psychiatrists diagnosed the patient with schizophrenia whereas only 2% of British psychiatrists gave the same diagnosis
Copeland gave a description of a patient to ___ US and ____ British psychiatrists
134
194
Copeland gave a description of a patient to 134 US and 194 British psychiatrists and found that ___ of the US psychiatrists diagnosed the patient with schizophrenia whereas only __ of British psychiatrists gave the same diagnosis
692
Evaluating reliability- Read
P- In addition, worryingly Read (2004) reported that test- retest analysis is as low as 37% for schizophrenia which is extremely concerning,
E- Especially when we consider the potential false positives and false negatives this could create. This suggests that some patients may not be diagnosed when they should - and as such miss out on key medication
E- Alternatively, it also implies that some patients may receive a schiz diagnosis, not actually need the diagnosis or the medication that goes with it
L -This could imply that clinicians need to take extra care when diagnosing patients to avoid false positives and negatives
What did Read find
Reported that test- retest analysis is as low as 37% for schizophrenia which is extremely concerning, especially when we consider the potential false positives and false negatives this could create.
Read reported that the test re-test analysis for diagnosing schiz was what?
37%
Evaluating reliability- improvement of the DSM
P- However, the DSM has also now improved the reliability of diagnosis through revising the criteria.
E- For example, DSM 5 has now stripped the criteria of trying to differentiate between bizarre and non-bizarre delusions from the diagnostic guide as it was difficult to complete and led to increased reliability problems in diagnosis
L- This supports the notion that the DSM has helped to increase the reliability of diagnosis by adapting and changing certain specific criteria to make diagnosis more consistent.
What are the two issues of validity in diagnosing schiz
Over-lapping symptoms comorbidity issues
Evaluating validity- Buckley
P - In evaluation, comorbidity reduces the validity of diagnosis as a clinician could make an inaccurate diagnosis due to the additional disorder.
E - Buckley et al (2009) identified the following comorbid conditions with schizophrenia and argues they could actually be subtypes of schizophrenia. The following was reported with schizophrenia: 50% with depression and 47% with substance abuse.
E - in addition - to complicate matters further, we are unsure as to which condition came first
L - This suggests that..the validity of diagnosing schiz is damaged by the presences of comorbid conditions
What did Buckley find
Identified the following comorbid conditions with schizophrenia and argues they could actually be subtypes of schizophrenia. The following was reported with schizophrenia: 50% with depression and 47% with substance abuse.
Buckley et al (2009) identified the following comorbid conditions with schizophrenia and argues they could actually be subtypes of schizophrenia. The following was reported with schizophrenia: __% with depression and __% with substance abuse.
50
47
Evaluating validity- re-considering comorbid conditions
P - In further evaluation, we must really re-consider comorbid conditions and schizophrenia.
E - As patients actually suffer from 2 or more mental health states for example, having both schizophrenia and post traumatic stress disorder - both with very specific symptoms and huge amounts of emotional distress
E -Surely that is a UNIQUE CONDITION as opposed to 2 states that coexist and receive 2 separate diagnoses. This has been partly addressed in DSM V, but problems remain with comorbidity and schizophrenia.
L-Therefore….DSM and other manuals will continue to refine diagnostic criteria to tackle the reality of patients suffering from 2 disorders and improve the validity of diagnosing schiz
Evaluating validity- Hewitt
P - An issue with overlapping symptoms is that they can decrease the validity of diagnosis as a clinician may identify symptoms which are common with other disorders.
E - Hewitt (2001) investigated the symptoms of autistic patients and patients of schizophrenia. They found that…
E - from 14 patients with schiz and 14 with autism- none of the schizophrenic patients had symptoms of autism, but 50% (7) of the autistic patients had symptoms of schizophrenia (particularly negative symptoms
L- This shows support for the fact that symptom overlap has the potential to damage the validity of diagnosing schiz
What did Hewitt do/find
Investigated the symptoms of autistic patients and patients of schizophrenia. They found that…From 14 patients with schiz and 14 with autism- none of the schizophrenic patients had symptoms of autism, but 50% (7) of the autistic patients had symptoms of schizophrenia (particularly negative symptoms
From __ patients with schiz and __ with autism- none of the schizophrenic patients had symptoms of autism, but __% (_) of the autistic patients had symptoms of schizophrenia (particularly negative symptoms
14
14
50
7
Evaluating validity- How DSM can help improve validity
P - In conclusion, classification systems such as the DSM can help to improve the validity of diagnosis due to having to meet more than one criteria.
E - For example with schiz, patients do not just need to show 2 symptoms, but also nowadays there is exclusion criteria (e.g. no major depression or manic episodes)
E - AND due to symptoms needing to be present for a certain time frame e.g. symptoms present for a month and disturbance for 6 months
L - This could help to make the diagnosis of schiz more accurate and hopefully avoid misdiagnosis
Four issues of cultural bias in diagnosing schiz
Cultural interpretations
Negative cultural attitudes to Schiz
The culture / nationality of the clinician
Race discrimination in diagnosing schiz
Evaluating cultural bias- Malgady
In evaluation, there is research into cultural differencesMalgady’s (1987) research has demonstrated that different cultures interpret symptoms of schiz in very unique ways. This research showed that in traditional Costa Rican culture hearing voices is interpreted as spirits talking to the individual (a prized abnormality), whereas in the USA the same phenomenon is interpreted as a core symptom of schizophrenia. This research implies..the cultures we find ourselves in impact on the diagnosis of schizophrenia
What did Malgady’s research show
Demonstrated that different cultures interpret symptoms of schiz in very unique ways. This research showed that in traditional Costa Rican culture hearing voices is interpreted as spirits talking to the individual (a prized abnormality), whereas in the USA the same phenomenon is interpreted as a core symptom of schizophrenia.
Evaluating cultural bias- practical applications
However there are strong practical applications that have come from research into cultural biases of the diagnosis of schizophrenia. Finding cultural biases allows for training for psychologists into the differences in interpretation and expression of symptoms in cultures. E.g. in Nigeria many patients may claim they have ants running all over their body (tactile hallucination)This can improve diagnosis because it should make clinicians more sensitive to subtle cultural norms and ways of expressing symptoms This implies that..by attending to cultural differences we can improve the validity of diagnosis schizophrenia
Evaluating cultural bias- culture impacts prognosis as well as diagnosis
In further evaluation not only does culture impact on diagnosis - it also affects prognosis of schizophrenia Recent research has actually implied that the recovery form Schiz is much more likely to occur in collectivist cultures compared to individualistic cultures This could be due to the greater interconnectedness of the these cultures and how when individuals suffer schiz and the accompanying emotional distress, others are more involved in their recovery This implies that exploring the significance of culture could have an influence on recovery from schiz as well its diagnosis
Evaluating culture bias- Copeland
There has been further support in research, the culture or nationality of the psychologist or clinician has shown to affect the rate of diagnosis. Copeland (1971) gave a description of a patient to 134 US and 194 British psychiatrists and found that 69% of the US psychiatrists diagnosed the patient with schizophrenia whereas only 2% of British psychiatrists gave the same diagnosis. This shows that American clinicians are far more likely to diagnose schizophrenia than their UK counterparts, suggesting the culture of the clinician does impact on diagnosis