Before we can decide whether the DSM and ICD are either reliable and/or valid we need to know a little bit about each of these classification systems.
I have provided a starting point here but feel free to research further.
The DSM
The DSM, published by the American Psychiatric Association (APA), originated from a system used to classify disorders experienced by World War 2 soldiers. It was first published in 1952 and has been revised several times. It is used all over the US and much of the Western world and generates considerable revenue for the APA, (American Psychological Association, 2018).The current version, DSM-5, was published in May 2013 and contains over 300 disorders, divided into over 20 categories.
Some important changes have been made in DSM-5, including the removal of what used to be called the ‘multi-axial’ system, which prompted a holistic approach to diagnosis by assessing general functioning and the impact of medical and/or psycho-social issues, such as bereavement or redundancy. Although, the multi-axial approach is no longer part of the DSM-5, it is clear that many of these issues will still be considered, (American Psychiatric Association, 2013).
Psychology All Stars: ‘Internet Gaming Disorder’, ‘Caffeine Use Disorder’ and ‘Selfie-it is’
In order to keep up with our ever-changing society, DSM 5 includes section 3, which lists suggestions for new disorders. These conditions seem sufficiently prevalent to deserve a place in the DSM, but currently there is insufficient t research on their reliability or validity. Some of the suggestions have caused a great deal of controversy including Attenuated Psychosis Syndrome. Two of the suggestions above are real disorders from Section 3 and one hit the headlines in 2014 but turned out to be an example of ‘fake news’. However, Professor Mark Griffiths at Nottingham Trent University has subsequently shown that this may indeed be a real disorder, worthy of a place in the DSM.
Which disorder do you think Griffiths has been researching? Do you think this should be viewed as a disorder?
Make a link – Developmental Psychology
Lifespan considerations
The DSM 5 is organised chronologically, with disorders which manifest early in life listed first, followed by those which become apparent in adolescence, then adulthood and finally old age. This organisational structure applies to the book as a whole, but also to each chapter and was adopted to ensure that lifespan information is used to assist in diagnostic decision-making.
The ICD
The International Statistical Classification of Diseases and Related Health Problems includes both physical and mental disorders. It originated from the 1893 International List of Causes of Death used to monitor global mortality and morbidity statistics (i.e. data on death and disease). In 1948, The World Health Organisation (WHO) became involved and like the DSM, the ICD has seen many revision overs the years. The current version, ICD10 was published by the WHO in 1992 and ICD11 is destined to be published in 2018. This multilingual, freely available resource is used by clinicians and researchers, policy makers and patient organisations around the world. It provides a ‘common language’ so that data collected in different countries can be usefully compared.
Mental disorders and ICD codes
Chapter 5 of ICD10 is entitled Mental and Behavioural Disorders (F00–F99) and contains eleven sub-categories. Each disorder has a code, starting with F. The number denotes the category of disorder, e.g. F40-48 are ‘neurotic, stress-related and somatoform disorders’. F40 relates to the sub-category of ‘phobic anxiety disorders’ and F40.1 relates to ‘social phobias’ in particular. Each section has a few ‘left-over’ codes, allowing new disorders to be added, without having to recode the other disorders. The codes are used for indexing medical records, making it easy to find examples of people with specific conditions, when conducting research for example. The system attempts to be comprehensive enough to include all known conditions but also to avoid repetition or overlap.
Changes over the years
Morton Kramer explains that ICD-5 had just four categories of disorder in 1938 and although considerable changes were made to ICD-6, Erwin Stengel (1959) concluded that this section needed a major overhaul. Like the DSM, reliability was a major issue compounded by the fact that the presentation, communication and interpretation of symptoms is shaped by language and culture, meaning that patients in one country might come away with a different diagnosis to patients in another country, despite presenting very similar symptoms. Likewise, patients may have very different symptoms, yet the same label might be applied to both. This posed problems for the international research community and thus the creation of a globally accepted glossary of terms was deemed beneficial.
Creating a more reliable and valid system
A rigorous research programme was set up to review differences in diagnostic practice and differing use of diagnostic terminology across the world. Dozens of international conferences, seminars and workshops took place. Delegates from many countries diagnosed patients using video clips and discussed the issues with each other. International interview schedules were developed to facilitate a common assessment process, allowing comparisons to be made. This process helped to reveal inconsistencies, ambiguities and overlaps between disorders, which were then removed from the ICD. The ICD-10 is now described as clear, simple and logically organised. Psychiatrists are encouraged to indicate whether a diagnosis is ‘provisional’ or ‘tentative’, i.e. in the absence of sufficient information or whether they are ‘confident’ in their decision.
ICD-10 field trials
There are two different versions of the ICD; one for clinicians and one for researchers. The latter is called the Diagnostic Criteria for Research (DCR) and contains more detailed descriptions of the disorders and symptoms. Norman Sartorius and colleagues (1995) reported the findings of the DCR field trials which involved eleven thousand patient assessmen
ts and nearly one thousand clinicians from 32 different countries. Although most disorders showed good reliability, some had lower reliability e.g. mild recurrent depressive disorder, (Kappa 0.3). Generally, clinicians found the document easy to use although they said disorders with overlapping and mixed symptoms, e.g. mixed anxiety and depressive disorder were more challenging.20 mark classificastion randomiser
Why do you think reliability of diagnosis might be more important in research than in clinical practice?
Cultural differences lead psychiatrists to make differing diagnosis
A study by Barry Gurland et al. in 1970 demonstrated that psychiatrists in New York, in the United States were more likely to diagnose patients with schizophrenia than affective disorders whereas psychiatrists from London , in the United Kingdom. Gurland sought to reveal whether his was due to differences in the patients themselves and found that the differences in fact were due to differences in the clinicians. This shows that individual differences in the cultural background, experience and training of psychiatrists can affect their interpretation of symptoms, leading to differential diagnosis.
Use your textbooks and other sources to find out about the DSM and ICD classifications systems.
- Create a brain map of facts about the DSM; use the following questions starters to structure your notes: what, when, where, who, why, how? These are always useful prompts to get you to write more in a description, cueing you to remember more details.
- Make sure that the WHAT “branch” on your brain-map has a “twig” entitled multi-axial system and then explain each axes in BRIEF
- How is axis 2 related to deviance?
- How are axis 4 and 5 linked to the 4 Ds of diagnosis?
- Make another brain map with facts about the ICD; remember to use what, when, where, who, why, how?
- What percentage of practitioners use the ICD compared with the DSM in the study by Reed et al (2011)
Now you have learnt to describe each system, we can compare them and start to evaluate them:
We will use this activity to compare the two, the document contains phrases that relate to either DSM or ICD, you have to match the phrase to the correct classification system. Mix and match activity: icd-dsm-sorting-actiivty
Once you have done this, use the table to organise your thoughts about these facts; this will help you to start evaluating each system: classification-systems
The following documentaries will provide a useful introduction to the topics:
Wider reading
Update on the progress of the ICD 11 which is not out still but imminent:
http://www.who.int/classifications/ICD11January2017Newsletter.pdf?ua=1
Practice Questions
- The DSM and the ICD are classification systems that are helpful for making diagnoses of mental disorders. Compare the DSM IV or V and the ICD 10. (2)
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