A Taxometric Study of Hypochondriasis Symptoms Susan L. Longley Rosalind Franklin University of Medicine and Science Joshua J. Broman-Fulks Appalachian State University John E. Calamari Rosalind Franklin University of Medicine and Science Russell Noyes University of Iowa Michael Wade SUNY Upstate Medical University, Syracuse Carissa M. Orlando Appalachian State University Hypochondriasis has been conceptualized as both a distinct category that is characterized by a disabling illness preoccupation and as a continuum of health concerns. Empirical support for one of these theoretical models will clarify inconsistent assessment approaches and study designs that have impeded theory and research. To facilitate progress, taxometric analyses were conducted to determine whether hypochondriasis is best understood as a discrete category, consistent with the DSM, or as a dimensional entity, consistent with prevailing opinion and most self- report measures. Data from a large undergraduate sample that completed 3 hypochondriasis symptom measures were factor analyzed. The 4 factor analytically derived symptom indicators were then used in these taxometric analyses. Consistent with our hypotheses and existing theory, results supported a dimensional structure for hypochondriasis. Implications for the conceptualization of hypochondriasis and directions for future study are discussed. HYPOCHONDRIASIS HAS LONG PUZZLED medical and mental health professionals as it is often misidenti- fied and largely presents in medical, rather than mental health, clinics (Barsky & Klerman, 1983; Berrios, 2001; Noyes, in press). Analyses of two prevailing perspectives on hypochondriasis have the potential to increase understanding of this disturbance and its core phenomenology (Noyes, in press). According to the medical perspective hypochondriasis is a discrete disease entity that is defined by a persistent belief in and fear about having a serious illness despite medical reassurance (Cohen, 1961; DSM-IV-TR; American Psychiatric Association [APA], 2000) . According to the Available online at www.sciencedirect.com Behavior Therapy 41 (2010) 505 – 514 www.elsevier.com/locate/bt Address correspondence to Susan L. Longley, Ph.D., Department of Psychology, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064; e-mail: susan.longley@rosalindfranklin.edu. 0005-7894/10/505–514/$1.00/0 © 2010 Association for Behavioral and Cognitive Therapies. Published by Elsevier Ltd. All rights reserved.