Sunday, August 21, 2016

Indexing Versus Diagnosis - A Non-trivial Difference?

There was an interesting article written by Kenneth S. Kendler, MD in this month's American Journal of Psychiatry.  It addresses a phrase that I have seen in typed evaluations that causes me to cringe: "The patient does/does not meet criteria for major depression."  I was asked why that phrase bothered me so much and I basically pointed out that I don't care whether a person "meets criteria" for a specific DSM criteria - the overall assessment was more important to me.  Kendler describes the difference in terms of phenomenology - are there other aspects of depression that merit further description that what is in the DSM?  That seems true to me as well as, the time domain of symptoms development and how some of the critical symptoms may have developed.  On a developmental basis - sleep, anxiety, and depression all may have different time frame and given the length of time that the DSM approach has been around - there has been very little discussion of some of the key convergences and divergences.  Is primary insomnia beginning in middle school associated with depression in the twenties - the same problem as no insomnia in childhood and depression in the twenties.

To study the issue Kendler looks at 19 textbooks and 18 symptoms domains described in each of those textbooks.  He has specific criteria for textbook selection that resulted in 19 texts from 5 countries published between 1899 to 1956.  He included full criteria published by Wendell Muncie in 1939 and Aubrey Lewis in 1934 as being particularly instructive.  He looks at the number of authors describing a particular symptoms and additional descriptors of the symptoms they found in depressive states.  Just looking at neurovegetative states, the results are interesting.  The atypical depressive symptoms of hypersomnia and increased appetite and weight gain were essentially absent. Fourteen authors described sleep problems as initial insomnia or non restorative sleep.  Three authors described early morning awakening.  Poor appetite was listed by 10 authors and weight loss by 9 authors.  Anhedonia was listed by seven authors.  Kendler provides a detailed analysis of the remaining symptoms and how many of the authors consider these symptoms to be representative of depression.

One of the most instructive aspects of the paper was a direct comparison with DSM5 criteria across 18 symptoms, whether they are covered in the DSM and to what extent.  The symptoms not covered included volition/motivation, speech, other physical symptoms, anxiety, and depersonalization/derealization.  Experienced clinicians commonly encounter depressed people with all of these symptoms in everyday practice.  As an example, some of the most severely depressed people that I have treated were somatically focused to one degree or another on a continuum to the point of somatic delusions.  Adhering to DSM5 criteria would leave out the most important feature of their illness.  A more complete description of these symptoms allows for a better demarcation of the line between depression and psychotic depression - a critical line for developing a treatment plan.  Another critical aspect is the relationship between anxiety and depression.  The DSM tends to sacrifice a broader phenomenological approach for narrow, easily determined diagnostic markers.  Instead of describing the anxiety associated with depression, depressed patients often end up with additional diagnoses of anxiety disorders and in the DSM field trials it appears that anxiety and depression morph into on another and the criteria appear to have low diagnostic reliability in that context.

The broader concept from Kendler's philosophical perspective is whether meeting criteria is that same thing as having the disorder.  From a phenomenological perspective it is certainly possible to produce detailed analysis of patients that do not resemble one another in many regards.  Considering the fact that depression is always mapped onto unique conscious states that should not be too surprising.  Kendler's idea is that the DSM5 criteria do a "reasonable but incomplete job of assessing the prominent symptoms and signs of depression in the western post Kraepelinian tradition  ".  The idea of indexing cases of depression from what is not depression is relevant here.  I think that he should have been a little more specific in his criticism.  I don't think they do a reasonable job when they are not part of a psychiatric assessment by a psychiatrist who has enough time to do a good job.  Taking the DSM5 criteria and converting them into a checklist and applying that to the masses comes to mind.  This is probably the most absurd conclusion to the indexing concept, surpassed only by telling those who are screened that "you meet criteria for depression and that meets our health plan criteria to start citalopram".

 Kendler points out the consequences of reifying diagnostic criteria to the point that they become distinct disorders even in the absence of any quantitative markers.  Andreassen made similar arguments about DSM technology and the death of an interest in psychopathology in a previous paper (2).  Both authors seem to miss the mark in terms of what is really missed here.  The diagnostic nosology has shifted from a relative simple mind based paradigm to one that purports to pick up extreme conditions at the fringe of human behavior.  The accuracy of those diagnoses is less as the described disorders get more common.  Human consciousness appears to be the critical variable here and there remain very few commentators on this issue.  Psychiatric disorders become very complex once the psychiatrist goes far beyond symptom lists and even personality disorders and what is commonly considered personality traits to recognizing that the person in front of you is a truly unique conscious state associated with a unique neurobiological state.


George Dawson, MD DFAPA


1: Kendler KS. The Phenomenology of Major Depression and the Representativeness and Nature of DSM Criteria. Am J Psychiatry. 2016 Aug 1;173(8):771-80. doi: 10.1176/appi.ajp.2016.15121509. Epub 2016 May 3. PubMed PMID: 27138588.

2: Andreasen NC. DSM and the death of phenomenology in America: an example of unintended consequences. Schizophr Bull. 2007 Jan;33(1):108-12. Epub 2006 Dec 7. PubMed PMID: 17158191; PubMed Central PMCID: PMC2632284. (full text)


Quote at top is from reference 1 by Dr. Kendler.

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