Realism and operationism in psychiatric diagnosis

Abstract

In the context of psychiatric diagnosis, operationists claim that mental disorders are nothing more than the satisfying of objective diagnostic criteria, whereas realists claim that mental disorders are latent entities that are detected by applying those criteria. The implications of this distinction are substantial in actual clinical situations, such as in the co-occurrence of disorders that may interfere with one another's detection, or when patients falsify their symptoms. Realist and operationist conceptions of diagnosis may lead to different clinical decisions in these situations, affecting treatment efficacy and ultimate patient outcomes.

• Philosophy of Science
• Psychiatric Diagnosis
• Psychometrics

Acknowledgments

The authors thank Colin Allen, Alex Jordan, Corey McCall, and Steven Nydick for their comments on previous drafts of this paper.

Notes

[1] According to Bridgman (1927) “a concept is synonymous with the corresponding set of [measurement] operations” (p. 5). Stevens (e.g., 1935) applied Bridgman's operationism to the measurement of mental phenomena, leading to a methodological dictum: “every scientific concept must be accompanied by a rule for its application which is expressible solely in terms of acts of denoting and associated discriminations” (Hardcastle, 1995, pp. 408–409). In the area of psychopathology, some scholars (e.g., Borsboom, 2008) prefer the label “constructivism” to “operationism” but the former label is often associated with “social constructionism,” and so we use “operationism” throughout the paper.

[2] Our reference to “contemporary operationism” is not meant to suggest that operationism is a live position in contemporary philosophy of science, only that it informs a particular contemporary approach to the study of psychopathology.

[3] One may dispute whether Figure 1(b) should be considered a measurement model at all, since it is unclear how mere classification is an instance of measurement. This is a live issue in the philosophy of psychometrics, but it is beyond the scope of this paper. For the sake of our argument we do not dispute the operationists’ claim that nominal measurement is true measurement (for further discussion, see Borsboom, 2005; Johnson, 1936; Michell, 1999).

[4] The change in terminology from “mental retardation” to “intellectual disability” is nearly complete in the scholarly literature on the topic, but certain official diagnostic references that have not been updated in the past few years refer to mental retardation. For more on the change in terminology, see Schalock, Luckasson, and Shogren (2007).

[5] Although this vignette is hypothetical, it closely resembles an actual clinical case assigned to the first author when he was performing psychological evaluations at a preschool center for children with disabilities.

[6] One implication of this realist conception of validity is that reliability and validity are independent, since variation in a latent trait may produce variation in test scores even when a test is unreliable (Borsboom, 2005; Hood, 2009). In contrast to this view, the classical (operationist) view asserts that reliability is instead part of validity, in part because reliability constrains the ability of a test to predict other variables (Hogan, 2007).

[7] Although a jump in IQ from 60 to 80 may seem very large, young children do not show very stable IQ test performance, so a shift of 20 points would not be very unusual.

[8] There are a wide variety of effort tests (Boone, 2007), but most are very simple measures of memory, reading, and other cognitive processes that appear to be more difficult than they actually are. The tests are presented to the examinee as being sensitive to the presence of a disorder such as ADHD, but they are actually so easy that even individuals with the disorder do quite well on them. A low score, then, is a reliable sign of malingering.

Additional information

Notes on contributors

Benjamin J. Lovett

Benjamin J. Lovett is Assistant Professor of Psychology at Elmira College.

S. Brian Hood

S. Brian Hood is Visiting Assistant Professor of Philosophy at the University of West Florida.