Jablensky2016 - Psychiatric classifications, validity and utility

  • Type:#article
  • Year read:#read2022
  • Subject: (in brackets, can also bracket keywords in text)
  • Bibtex: @jablensky2016
  • Bibliography: Jablensky, A. (2016). Psychiatric classifications: Validity and utility. World Psychiatry, 15(1), 26–31. https://doi.org/10.1002/wps.20284

Example citation

Psychiatric diagnoses are not separated by natural boundaries and the pathophysiology is not well understood, thus they are not diseases in the strict sense. However, psychiatric diagnoses are still useful in everyday clinical practice because they hold information about symptoms and treatment response [@jablensky2016].

Key takeaways

  • Most psychiatric disorders are not valid because they are not separated by natural boundaries.
  • Diagnoses have utility because they hold information about symptoms, outcome, treatment response and (in some cases) aetiology.
  • Category vs Dimensional view still an open question.
  • Psychiatric disorders don’t have disease status since Germ theory of disease is lacking underlying causes.
    • Alzheimer’s diseas is approaching disease construct, we have some understanding of the underlying pathophysiology but it’s still in development.
    • Most psychiatric disorders have only achieved syndrome status (cluster of symptoms).
  • If we claim discrete diseases in psychaitry, we should establish correlations among symptoms and there should be a Zone of rarity between conditions.
    • Large genetic overlap and very general environmental risk factors provide evidence that disorders are likely not discrete.
  • DSM and ICD should not be seen as systematic classifications in the strict sense, because the categories are not mutually exclusive and each category is not jointly exhaustive to account for all possible entities. We should view DSM and ICD as pragmatic tools for everyday communication.
  • With the current classification system we have decent Reliability but the Validity is less clear.

…the protagonist of modern psychiatric nosology E. Kraepelin stated in one of his last articles, Patterns of Mental Disorder, that “it is necessary to turn away from arranging illnesses in orderly well-defined groups, and to set ourselves the undoubtedly higher and more satisfying goal of understanding their essential structure.” This goal of validity is yet to be attained.

Schizophrenia may be an invaluable concept to practicing psychiatrists, but of questionable use to researchers exploring the genetic basis of psychosis. For example, the DSM-5 definition of schizophrenia is useful for predicting outcome, because some degree of chronicity is inbuilt. But a broader definition, covering a heterogeneous “schizophrenia spectrum”, is more useful for defining a syndrome with high heritability for genetic research.