ao3 - issues with classification and diagnosis

• what is inter-rater reliability?

   the extent to which different assessors agree on their assessments
• inter-rater reliability in the context of sz

  the consistency of diagnosis between those making the diagnosis
• PEEL - inter-rater reliability (point)

  There are issues with inter-rater reliability when it comes to diagnosing schizophrenia
• inter-rater reliability (evidence)

  Cheniaux et al (2009) asked 2 psychiatrists to independently diagnose 100 patients using both the ICD and the DSM.
• inter-rater reliability (elaboration)

  She found 1 psychiatrist diagnosed 26 as schizophrenic according to the DSM and 44 according to the ICD. The other psychiatrist diagnosed 13 as schizophrenic according to the DSM and 24 according to the ICD.
• inter-rater reliability (link)

  This is a limitation in the area of diagnosis as it shows diagnosis will vary depending on who is making the assessment and there is a fundamental lack of agreement amongst health care professionals.
• criterion validity

  the extent to which different assessment systems arrive at the same diagnosis for the same patient
• criterion validity in the context of sz

  the manual used correctly when diagnosing schizophrenia or mistaking it with another illness
• validity (point)

  There are limitations with criterion validity when diagnosing schizophrenia
• validity (evidence)

  In the Cheniaux et al study, there was a greater frequency of diagnosis by both psychiatrists when using the ICD compared to the DSM.
• validity (elaboration)

  This would suggest using the ICD is leading to over diagnosis of schizophrenia or using the DSM is leading to under-diagnosis of schizophrenia
• validity (link)

  This is a problem as it shows one of the manuals is not accurately measuring schizophrenia. As different manuals are used in different countries then a large number of patients are going to be negatively affected by this.
• what is co-morbidity

  two or more conditions occurring together
• co-morbidity in the context of schizophrenia

  if the conditions occur together most of the time, it questions the validity of the diagnosis as there may be mistakes or a separate single condition
• co-morbidity (point)

  High co-morbidity rates in schizophrenia suggest a lack of understanding about the illness
• co-morbidity (evidence)

   Buckley et al (2009) found 50% of schizophrenia patients were also diagnosed with depression
• co-morbidity (elaboration)

  Additionally, patients were highly co-morbid for substance abuse, PTSD and OCD
• co-morbidity (link)

  This would suggest there may be an issue where psychiatrists are unable to tell the difference between the 2 disorders OR that when the 2 disorders appear in tandem that it may actually be a totally different singular disorder. Regardless of which, we still do not fully understand the illness and the symptoms which accompany it.
• what is symptom overlap

  symptoms of one disorder that are also present in a different disorder
• symptom overlap in the context of schizophrenia

  bipolar disorder also involves positive symptoms (e.g delusions) and negative symptoms (e.g avolition)
• symptom overlap (point)

  A limitation with diagnosing schizophrenia is the degree of similarity between this and other disorders
• symptom overlap (evidence)

  The symptoms of schizophrenia overlap with many disorders
• symptom overlap (elaboration)

  For example, Bipolar disorder involves positive symptoms such as delusional thinking and negative symptoms such as avolition
• symptom overlap (link)

  This not only makes it difficult to distinguish between the 2 disorders but also questions whether these 2 similar disorders might actually be the same disorder.
• what are cultural norms

  shared beliefs and the human behaviours that support these values within society
• what are cultural norms in the context of schizophrenia

  hearing voices in some cultures is a cultural norm 
• cultural bias (point)

  There seems to be a high degree of cultural bias when diagnosing schizophrenia which is evident by the higher rates of diagnosis of both African-Caribbean and African-American people. 
• cultural bias (evidence)

   Pinto & Jones (2008) found British people of Afro-Caribbean descent are 9 times more likely to be diagnosed with schizophrenia than white British people.
• cultural bias (elaboration)

   However, this is not true of those who live in Afro Caribbean countries
• cultural bias (link)

  This suggests it is unlikely to be a genetic vulnerability and is in fact due to cultural bias where psychiatrists of a different cultural background are misinterpreting culturally specific behaviours as symptoms of schizophrenia
• what is gender bias

  when differences between the genders are overestimated or ignored
• gender bias (point)

  There may be an issue of gender bias in the diagnosis of schizophrenia where more men than women are diagnosed with the illness
• gender bias (evidence)

  Men are more likely to be diagnosed with schizophrenia at a rate of 1:1.4
• gender bias (elaboration)

  Cotton et al (2009) found that female patients typically function better than men, being more likely to work and have good family relationships. Strong interpersonal functioning by women may bias doctors to under diagnose schizophrenia
• gender bias (link)

  This strong interpersonal functioning could mask the fact they have schizophrenia or the severity. This questions the validity as the procedures for diagnosis work well only on patients of one gender.