ORIGINAL ARTICLE Explicit and Implicit Anxiety: Differences Between Patients with Hypochondriasis, Patients with Anxiety Disorders, and Healthy Controls Florian Weck • Gaby Bleichhardt • Michael Wittho ¨ft • Wolfgang Hiller Published online: 10 March 2010 Ó Springer Science+Business Media, LLC 2010 Abstract Empirical research has found comparable levels of anxiety in patients with hypochondriasis and those with various anxiety disorders. However, the majority of these investigations were based exclusively on questionnaires (Q-data). In the present study, we included the implicit association task-anxiety (IAT-anxiety; Egloff and Schmukle in J Personal Soc Psychol, 83:1441–1455 2002) as an implicit test (T-data) of anxiety. Results showed that patients with hypochondriasis (n = 36) and those with anxiety disorders (n = 25) did not differ with respect to explicit (brief symptom inventory) or implicit measures (IAT-anxiety) of anxiety, with both groups exhibiting higher values than healthy controls (n = 34). For measures of hypochondriacal attributes (illness attitude scales), patients with hypochondriasis exhibited the highest values, and the values of patients with anxiety disorders lay between those of healthy controls and those of hypochon- driacal patients. The results indicate a clear overlap between hypochondriasis and anxiety disorders with respect to explicit and implicit measures of anxiety. Keywords Hypochondriasis Á Anxiety disorders Á Implicit association test Á Health anxiety Á Illness behavior Introduction The fact that the main criterion for the diagnosis of hypochondriasis is fear of having a serious disease (APA 2000) indicates that there is a strong association between hypochondriasis and anxiety. Empirical research based on a variety of samples has demonstrated significant correla- tions between hypochondriacal fears, beliefs, and attitudes on the one hand, and anxiety on the other (Kellner et al. 1987). Such relationships have been found in psychiatric patients (e.g., Kellner et al. 1992) as well as in participants from the general population (e.g., Weck et al. 2009). It has further been found that 86% of patients with hypo- chondriasis have one or more additional anxiety disorders (Barsky et al. 1992). Typically, patients with hypo- chondriasis also exhibit symptoms of anxiety disorders such as panic disorder and obsessive compulsive disorder, although the symptoms are less pronounced (Deacon and Abramowitz 2008). There is evidence of a broad symptom overlap between hypochondriasis and several anxiety disorders, in particular for panic disorder, generalized anxiety disorder, and obsessive compulsive disorder. Many studies have identi- fied hypochondriacal characteristics in patients with these anxiety disorders (for an overview, see Noyes 1999). However, only a few studies have directly compared patients with hypochondriasis and patients with an anxiety disorder. An early investigation conducted by Noyes et al. (1986) revealed a strong overlap between patients with hypochondriasis and those with panic disorder in terms of hypochondriacal attributes. The authors compared the Whiteley-Index values (WI, Pilowsky 1967) of patients with panic disorder to those of hypochondriacal psychi- atric patients originally assessed by Pilowsky (1967) and F. Weck (&) Department of Clinical Psychology and Psychotherapy, University of Frankfurt, Varrantrappstraße 40-42, 60486 Frankfurt, Germany e-mail: weck@psych.uni-frankfurt.de G. Bleichhardt Department of Clinical Psychology and Psychotherapy, University of Marburg, Marburg, Germany M. Wittho ¨ft Á W. Hiller Department of Clinical Psychology and Psychotherapy, University of Mainz, Mainz, Germany 123 Cogn Ther Res (2011) 35:317–325 DOI 10.1007/s10608-010-9303-5