What to expect from reliability and validity claims? A pragmatic conception of psychiatric nosology

Abstract

The reliability and validity of psychiatric diagnoses have always been a major concern. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) reliability field trials yielded ambiguous results, with some diagnostic categories scoring well below par. We argue that the emphasis on the reliability of psychiatric diagnoses, which has dominated psychiatric nosology and guided the endeavor of improving the DSM in its consecutive editions, is misguided and lacks in structural validity. In this article, we defend a pragmatic view on psychiatric disease as the most fruitful approach to an understanding of what the categorical distinctions in the DSM (can) represent. Disorders in the DSM are descriptions of clinical pictures and do not necessarily correspond to an identified pathological substrate. Although this is a logical result of the nature of psychiatric disease, it bears important consequences. The various DSM disease categories are not uniform but should be regarded as representing different kinds of disorders, ranging from a separation from normal behavior based on practical grounds to the discrete kind of disorders envisioned by proponents of a strong realistic view. We argue that the explication of kinds of disorders outlined in this article provides interesting perspectives on the problems of reliability and validity that the DSM faces.

Reasoning, evidence, and clinical decision‐making: The great debate moves forward

“…The history of ideas reveals that key concepts (such as “the atom,” considered in a primitive form by the pre‐Socratics but convincingly criticized by Aristotle) can be sidelined for years or even centuries, only to be revived at a later point in history, modified in adaptation to a new intellectual context, to play a central role in theories representing real intellectual progress . What matters, as noted above, and as several contributions to this edition confirm, is that theory performs the role of making sense of practice—of actually helping practitioners to understand and improve the work they do. Theories that fail to do this, that form an obstacle to further improvement, can be rejected for that reason.…”

“…This argument is followed by two papers from Diogo Telles Correia, the first of which provides a helpful summary of different perspectives on validity within psychiatry, grounding the discussion in broader accounts of the term as employed in philosophical and scientific discourse . The discussions of “realistic versus instrumental” validity resonate with the concerns of Lefer et al Correia's second paper provides another useful summary, this time of the history of the concept of “psychiatric validity,” before making some tentative suggestions about its future evolution—arguing that explicit recognition of “the specificity of psychiatry, a hybrid discipline between human sciences and neurosciences, may be the first step towards a paradigm shift.”…”

“…Juliette Brown's paper brings together clinical experience and the ideas of theorists including Hume, Buber, Levinas, and Lacan to throw light on our individual and cultural understandings of dementia and its relationship to self and identity over time . She notes that dementia is understood in our culture as being “synonymous with loss” but argues that this is due to our “conscious and unconscious focus on the later stages of the illness.” This focus can undermine our abilities to think about and use “the intervening years”—years which can “deliver remarkable insights into the capacity to navigate fragmented identities.” Focussing on the social nature of identity as “a relational, interactive quality,” Brown examines ways of avoiding the objectification and disempowerment of persons with dementia, utilizing our experience of attachment to facilitate “an empathic response to others” which embodies “an assumption of their value.” In academia, the term “fuzzy,” when applied to someone's reasoning, is typically used pejoratively, but this paper (and indeed the one which immediately follows it in this edition) strikes us as an excellent illustration of the pragmatic or (in a very positive sense) “fuzzy” approach to understanding clinical categories and practical reasoning advocated by Lefer et al…”

“…Their insightful analysis is followed by three papers discussing the concept of psychiatric validity. Sander Lefere and colleagues argue that discussions of psychiatric nosology have been dominated by an emphasis on the reliability of psychiatric diagnoses. They argue that this emphasis is misguided and responsible for the major concerns that have been raised about successive editions of the Diagnostic and Statistical Manual.…”

“…In this edition, we present an array of up‐to‐date analyses of the problems of reason in practice, addressing a diverse range of healthcare contexts and methods, considering policy decisions as well as specific instances of clinical reasoning . Contributors discuss the nature of practical wisdom, the relationship between reasoning, emotion, intuition, and evidence, and the sense in which EBM is (or is not) a “modern” scientific enterprise, in the light of considerations of the relationship between science, context, and culture .…”