Clinicians' conceptualizations of comorbid cases: a test of additive versus nonadditive models

• Published in: Journal of clinical psychology Vol. 66; no. 10; pp. 1121 - 1130
• Main Authors: Keeley, Jared, Blashfield, Roger K.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-10-2010; Wiley; Wiley Periodicals Inc
• Subjects: Biological and medical sciences; Clinical psychology; Cognition & reasoning; Comorbidity; Concept Formation; Diagnostic and Statistical Manual of Mental Disorders; DSM; Florida; Health Personnel; Health staff related problems. Vocational training; Humans; Medical sciences; Models, Theoretical; Nosology. Terminology. Diagnostic criteria; Psychology. Psychoanalysis. Psychiatry; Psychopathology; Psychopathology. Psychiatry; Social psychiatry. Ethnopsychiatry; Surveys and Questionnaires; Techniques and methods; Florida; Human; Health staff; Nosology; concept formation; Cognition; Experimental study; Concomitant disease; comorbidity; Criterion; Classification; Conceptualization; Diagnosis; Psychopathology; Diagnostic and Statistical Manual IV; Comparative study; DSM
• ISSN: 0021-9762; 1097-4679
• DOI: 10.1002/jclp.20713

Comorbidity in psychopathology is a common phenomenon. However, little is known about the way in which clinicians think about comorbid cases. The Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM‐IV‐TR; American Psychiatric Association, 2000) implies an additive model of concept combination, but studies of human cognition find that individuals often combine concepts in nonadditive ways. In this study, 70 clinicians listed symptoms for three disorders and their combinations. Participants produced nonadditive descriptions, termed overextensions, at significant rates. These results challenge the utility of the implicit additive model of the current DSM. © 2010 Wiley Periodicals, Inc. J Clin Psychol 66:1–10, 2010.