Behavioural Science Blog

The Science of Human Behaviour

Posts Tagged ‘Classification

Why a Computerized Decision System does not always lead to the Correct DSM-Classification

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According to Lars Bergman there are several reasons that keep computerized systems from producing the correct DSM-classification. The most important point might be that diagnosis in psychiatry is just to complex for a fully structured system to reach a good level of validity. Dynamic systems and appropriate statistics might be necessary. According to Dreyfus the intuition of the expert is an important part of the diagnostic process. This would also mean that the (paper version of the) SCID does not yield the expected validity. Other reasons are related to methodological problems of the study at hand: Most physicians used the computer version of the SCID for the first time. They also received only limited training and thus the computerized process might have interfered with their normal skills. Also the rule-following and logical step-by-step procedures designed for non-experts might have influenced validity.


Written by Martin Glanert

November 22, 2008 at 6:47 pm

The descriptive approach of the DSM – why clinicians love it – and don’t adhere to it anyway

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In medicine, diseases are classified according to the physiological problem that is presumed to have caused the disease. Classification is guided by advanced biological and chemical theories that have proven to have explanatory value. For mental illnesses that is a different story, because the working mechanism is mostly unknown and there is no unified scientific framework that can explain the abnormal processes. Mental health professionals for different schools might explain any given symptom according to a different theory. In that light the DSM was created to be purely atheoretical and give a minimal framework on which everyone involved could agree upon. The resulting manual has helped communication about mental illnesses and has fostered comparable research in the field of mental health. However it is questionable if the structure of the DSM is compatible with the reality of humans, who (for the most) are driven by the unstoppable urge to make sense of their environment. Indeed it was found in many studies that therapists often classify without adhering to the specific rules laid out by the DSM. They are guided by internal rules, that work in a different way than the DSM checklist. For example therapists regard some symptoms as more important for a specific diagnose than others (concept of centrality). The DSM on the other hand usually assigns equal weights to all factors. Because the concept of centrality has profound influence on memory and other cognitive processes the therapist’s personal theory plays an important role in the classification. I believe that the DSM should be regarded as a tool supporting communication that allows discussion about the different theories at hand. It can and will not replace the theories people have. If a theory based classification system is available (for a specific disease) it should be used next to or instead of the DSM.

Written by Martin Glanert

September 26, 2008 at 10:01 am