5.1.2 classification systems (DSM ICD) Flashcards
what is the DSM
the DSM describes the symptoms, features and associated factors of over 300 mental and behavioural disorders arranged into 22 categories. it is widely used throughout the US and in many nations across the world and generated considerable revenue for the APA which produce it. it is based on a classification system that was used to identify disorders experienced by WW2 soldiers and was first published in 1952 but has been revised several times. the system arguably provides an important first step on the journey to appropriate support however erroneous diagnosis can lead to labelling, stigmatisation and ineffective treatment
making a diagnosis using the DSM: how reliability and validity are assessed
spitzer the chair of the DSM 3 introduced the use of cohen’s kappa to improve the reliability of DSM 3. this statistic is written as a decimal and refers to the proportion of people who receive the same diagnosis when assessed and then re-assessed either at a later time (test-retest reliability) or by an alternative practitioner (inter-rater reliability)
spitzer and his colleagues felt that 0.7 would indicate ‘good agreement’ (spitzer et al 2012).
over the years, disorders have been removed and added to the different versions of the DSM. the validity of these labels has sometimes been criticised. there are several types of validity relevant to diagnosis.
making a diagnosis using the DSM: how reliability and validity are assessed
what is descriptive validity
when two people with the same diagnosis exhibits similar symptoms we say the diagnosis has descriptive validity
making a diagnosis using the DSM: how reliability and validity are assessed
what is aetiological validity
when they share similar causal factors this is referred to as aetiological validity
making a diagnosis using the DSM: how reliability and validity are assessed
what is concurrent validity
it’s established when a clinician uses more than one method or technique to reach a diagnosis and both methods ela’s to the same diagnosis
give strengths or the reliability of the DSM
good level of agreement for some disorders : field trials demonstrated impressive levels of agreement between clinicians for a variety of disorders
for example darrel regier et al 2014 reported that 3 disorders including ptsd had kappa values of 0.60 - 0.79, while 7 more diagnosis including sz has kappa values of 0.4-0.59
this is a strength because clinicians agreed with each other 0.6-0.79 and shows more objectivity and using dsm= more confident and better treatment
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goldstein 1988 found reliability for the diagnosis of SZ. goldstein rediagnosed 199 sz patients using DSM 3 and also asked other experts to do the same (single blind technique). high level of agreement and inter rated reliability, and as later version of the DSM have focused on improving validity and reliability it is likely that DSM 5 also has similar reliability
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David Kupfer & Helena Kraemer 2012) explain that clinicians who were part of the
DSM-5 field trials were asked to
‘work as they usually would’ and take clients as they come in order to mirror normal practice. In contrast, DMS- Ill used carefully screened ‘test’ clients and clinicians were given training in detail. It is therefore unsurprising that the DSM-5 had lower levels of reliability. this means that it is reliable as it mirrors normal day to day life. 0.7 = artificial. the testing for dsm 3 was artificial. dsm= natural so more reliable
give weaknesses of the reliability of the DSM
rests on the question of whether one person’s set of symptoms would lead to a common diagnosis by different physicians. if different physicians give different diagnosis for same symptoms then the diagnosis is not reliable and treatment might not work = falling standards
a weakness is that what counts as an acceptable level of agreement has plummeted over the last 35 years. rachel cooper 2014 explains that the DSM5 task force classified levels as low as 0.2-0.4 as acceptable. one of the least reliable diagnosis 0.28 was major depressive disorder = falling standards. This evidence suggests that the DSM may be less
reliable than previous versions and that diagnosis
of MDD, e.g. may have been made in error, while
other cases may have been missed altogether.
This is a weakness because…
people are missing out on meament / not getting treatment
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Stetka dn Ghaemi (2014) suggest that less than
50% clinicians had moved to using DSM-5 over
concerns of reliability. Cooper adds that 0.6
reliability means a person with sz is only 60% likelyto be re-diagnosed by a different clinician as
having sz which is unacceptable. In 1974 Spitzer said 0.7 kappa was only satisfactory - yet DSM-5 is 0.6 for sz. In DSM-Ill sz diagnosis had kappa of
0.81, and in DSM-5 just 0.46 in the trial. This
shows that expectations of reliability have
changed between the earlier versions and the
more recent DSM-5 where 0.2-0.4 is seen as
acceptable and 0.6-0.8 was very good.
give strengths of the validity of the DSM
a strength of the DSM-IV-TR was that evidence supports the validity of certain disorders
For example, Julia Kim-Cohen et al. (2005) demonstrated the concurrent validity (when the result of a study or set of data matches results from another done at the same time) of conduct
disorder (CD) through interviewing children and their mothers, observing the children’s anti-social behaviour and using questionnaires completed by
the children’s teachers. Specific risk factors e.g., male, low income and parental psychological disorders were common in many cases suggesting
sound aetiological validity.
Furthermore, predictive validity was demonstrated - 5-year-old children with CD were significantly more likely to
display behavioral and educational difficulties aged 7.
this is a strength because she demonstrates multiple types of validity that supported the disorder through the DSM
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@ Hoffman (2002) looked at alcohol abuse, alcohol dependency and cocaine dependence. The study looked at prison inmates and looked to see if differences showed up using a computer-
prompted structured interview would correspond to the DSM-4. Found that the diagnosis was valid and the interview data supported the idea that
dependence was a more sever syndrome than abuse. Symptoms matched the DSM. this shows that the dsm is valid as the diagnosis was the same even when using a computer structured interview
give weaknesses of the validity of the dsm
Labels tell us nothing about causes
A weakness is that many psychologists feel that the DSM-5 lacks validity.
The publication of the DSM 5 led to a storm of
criticism from psychiatrists and psychologists
claiming that psychiatric diagnosis tells us nothing
about what is causing a disorder. The argument is
that naming or classifying a disorder does not
actually tell us anything about the causes.
the arguments are circular: Why is a person hearing voices? Because they have SZ. How do we know they have SZ? Because they are hearing voices. The results of a diagnosis is simply a label that tells us nothing useful. this is a weakness because it doesn’t say anything about the causes which would play as major factor in treatment as not all SZ patients need the same treatment
Additionally, DSM lacks construct validity; you can
not ‘operationalise’ depression - as you lose
something of an understanding of the whole
experience and nature of depression. A list of symptoms does not provide this.
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Pies (2013) said DSM-V was “useful but
incomplete’, and an “informative but fallible
guide’, and did not offer a ‘comprehensive
likely understanding of the patient’
what is the ICD
the ICD is the international classification of diseases
used more frequently than the dsm in some parts of the world
the icd addresses all diseases, not just these involved in mental health disorders
the icd includes a look at the general health of a population which is used to monitor incidence and prevalence of illnesses
it is the icd that provides mortality rates and morbidity (n.of diseases) for WHO. all WHO member states use these figures
each section has a few left over codes, allowing new disorders to be added, without having to recode the other disorders
worldwide usage of ICD-10 : reed et al 2011= 70% of ppts used ICD10 when diagnosing MH disorders, 23% used DSMIV
Evana et al 2013= 51% used ICD10, 44% used DSMIV. usa used ICD9 until 2014
compare the ICD and DSM
reed 2013 suggests a n.of reasons for changing from the DSM to ICD.
ICD is produced by WHO, dsm is produced by APA which is a single nation professional body
the ICD is free and open resource, whereas the DSM is a revenue income for APA
the ICD is multilingual whereas the DSM is US dominated and in english only
the ICD covers all health condition while DSM only covers mental health disorders
definition of ICD
the icd contains both physical and psychological disorders and both are coded in the same way. the clinician selects key words from an interview with a client that relate to their symptoms - eg hallucinations, delusions. they will look up the symptoms or go straight to a section eg SZ
evaluate the reliability of the ICD
STRENGTH
Inter-rater reliability. A strength is a good consistency when two clinicians assess the same clients using the ICD-10. E.g. Galeazzi (2004) arranged for two researchers to conduct a joint interview to assess 100 consecutive clients for psychosomatic symptoms. The Kappa values ranged from 0.69 to 0.97 showing very high agreement. This encourages confidence for using the ICD-10 at least for some disorders.
STRENGTH: improvements between the ICD9 and 10 Ponizovsky et al (2006) conducted a large-scale longitudinal study found that PPV scores (the proportion of people who obtain the SAME diagnosis when reassessed) increased by 26% for SZ, 16% for
mood disorders and 8% for anxiety disorders. clearly showing improved reliability and suggests that the increased number of disorders from icd9 and 10 has not detracted from the reliability of these diagnoses
STRENGTH: Studies tend to show that the ICD-10 is a reliable measure of sz and it compares well with other measures (i.e. DSM-3). See Jakobsen et al 2005. Studies use inter-rater reliability and there are careful controls that ensure that the raters work independently to avoid bias.
SO OVERALL IT SEEMS THE ICD10 GIVES RELIABILITY WHEN IT COMES TO THE DIAGNOSIS OF SZ.
WEAKNESS: SZ was diagnosed more frequently when using the ICD10 that DSM 4 (cheniaux et al 2009), which suggests some lack of reliability between the two systems. but dsm says duration - 6mth, icd 1mth
evaluate the validity of the ICD 10
STRENGTH: Good predictive validity for SZ. A strength is that Peter Mason et al (1997) have shown that the diagnosis of SZ using the ICD-10 has good predictive validity. The study compared different ways of making a diagnosis. The ICD-9 and ICD-10 were reasonably good at predicting disability in 99 people with SZ 13 years later, as measured by the global
assessment of functioning questionnaire. This shows that the initial diagnosis was useful and meaningful in terms of its ability to accurately predict
future outcomes.
WEAKNESS
jansson et al 2002 suggested that ICD10 and DSM IV gave in excess 80% agreement which is high. but jansson found that different classification systems (icd9/10) focused on different symptoms and features
STRENGTH: Pihlajamaa et at (2008) compared diagnosis of sz of 807 sz spectrum patients using DSM III-R, DSM IV and ICD-10, to see alongside the Discharge Register diagnosis • DSM-IIIR Vs Register: 75% consistency • ICD-10 Vs Register 78% consist. Concl: when comparing, it could be seen that diagnosis were valid.
-jansson et al 2002 compared ICD9 and ICD 10 for SZ (concurrent validity). 155 patients in copenhagen. icd10 and dsm iv gave best diagnostic agreement (0.8)
Weakness: • However, some differences e.g. difference in diagnosis for some
individuals and between the
systems > concl: boundaries for sz
needed to be redrawn. ICD-9 focused
more on features (autism), and ICD-10
on psychotic phenom and neg
symptoms. SO, there is validity, but there are also differences
STRENGTH:
In general, when ICD-10 is used to diagnose Sz, the diagnosis matches a
diagnosis using a different system, suggesting the ICD is valid
• Jansson et al 2002 suggested that ICD-10 and DSM-IV gave in excess of
80% agreement: which is high
WEAKNESS: • Jansson et al 2002 found that different classification systems (ICD- 9/10 focused on different features and symptoms in Sz, which threatens the validity of the 2 systems. If a different focus, then validity is less likely. • Studies of validity of diagnosis of sz are hard given the differences in the disorders. The complexity of the issue therefore an issue. This is compounded as other disorders share similar features e.g. bipolar.
COMPARISON AND EVAL DSM AND ICD
DSM
ao1= published only in english
ao3= this is a weakness because it limits the amount of clinicians that can use it
ao1= provides a stream of revenue for the organisation who publish
ao3= weakness : ethical reasons, making it to make money. strength : the money made can be used for research
ao1= is specific to mental disorders and does not contain guidance on diagnosing physical health conditions
ao3= clinicians can’t look at the physical, if they even wanted to
ao1= is published by the APA, a single nation professional body
ao3= ethical issues : could just want to profit
ao1= only for use by psychiatrists
ao3= less accessible , prevents self diagnosing
ICD
ao1= multilingual
ao3 = allows the ability for the clinician to access in their native language. and allows more countries / cultures to use it
ao1= is a free and open resource
ao3= open to anyone and everyone so accessible for all clinicians, good for poorer countries
ao1= covers all health conditions as well as mental and behavioural
ao3= provides a capacity for clinicians to rule out behavioural to specifically diagnose a mental disorder and vice verca
ao1= is published by the WHO
ao3= increases the culture
ao1= can be used by a wide range of practioners
ao3= more accessible ie mental health workers can use it to refer people for serious intervention. developing nations can access it
