Classification in Psychiatry: The Move Towards ICD-11 and DSM-V.

Claudio E.M. Banzato


Curr Opin Psychiatry. 2004;17(6) 

In This Article

Abstract and Introduction

Purpose of Review: The intrinsic limitations of the current major diagnostic classifications have become increasingly apparent. Several constraints these diagnostic systems impose on clinical practice and research have led to a widespread perception that psychiatry must move beyond the nosologic model embodied in contemporary classifications. Thus, the present review covers the ongoing debate on key conceptual issues that may be relevant for the development of ICD-11 and DSM-V.
Recent Findings: The concepts of validity and utility, as applied to diagnostic classifications, received closer attention recently and attempts were made to better define and contrast them. Against such background, issues like conciliating the multiple purposes of diagnosis, choosing taxonomic strategies and determining the boundaries between and within (subtypes and specifiers) diagnostic categories and thresholds can be properly examined. Recent findings from genetics and neuroscience have added complexity to the already intricate field of mental disorders, raising high hopes of breakthroughs in pathophysiology. This bet on pathophysiology inscribes itself in the perennial debate about the nature of mental disorders and their defining (fundamental) level, which of course has critical implications for the future of psychiatry.
Summary: Despite considerable scientific advances achieved recently, the challenges faced by psychiatry have only been increasing in complexity. In the present state of affairs, conceptual closure and reductionism possibly represent the most serious risks to be avoided. The review ends by suggesting that methodological pluralism is a necessary condition for building a better psychiatric nosology.

'But in people, physiology is not the whole story, not because there is a soul or entelechy or élan vital in the presence of which the laws of physiology break down; rather it is because there is another story to which physiological knowledge is almost wholly irrelevant. (Notice that I did not say physiology is irrelevant, but only physiological knowledge; physis is relevant, but not our knowledge of physis)' (p.50). [1]

A diagnostic system should set the criteria to ensure accurate diagnoses and, consequently, proper treatment. However, if construed as a nosology, a diagnostic system must then mirror the state of the art of the discipline and lead heuristically to new hypotheses about the relationship of its diagnostic categories. In the last case, a classification is meant to serve as a nosologic framework onto which different kinds of conceptual and empirical problems faced by the discipline can be mapped. Thus, it is important not to inadvertently conflate diagnostic system and nosology, otherwise diagnostic validity and nosologic validity may be confused.[2*]

The complexities inherent in psychiatric nosology are so paramount that psychiatric classifications have been in need of explanation as much as the conditions they are supposed to account for. From this vantage point, after much vigorous debate over the last decades, it seems that the rule-based descriptive classifications, with their explicit but somewhat arbitrary diagnostic criteria, have not measured up to the high expectations for the prospective nosologic validation of their diagnostic categories.[3,4,5**,6] In the present review I explore a few conceptual issues that may be relevant for the move towards ICD-11 and DSM-V.