Determinants of Feature Centrality in Clinicians' Concepts of Mental Disorders

Determinants of Feature Centrality in Clinicians’ Concepts of Mental Disorders Woo-kyoung Ahn (woo-kyoung.ahn@yale.edu) Department of Psychology, 2 Hillhouse Avenue New Haven, CT 06520 USA Sarah Levin (slevin@hsph.harvard.edu) Department of Epidemiology, 677 Huntington Avenue Boston, MA 02115 USA Jessecae K. Marsh (jessecae.marsh@yale.edu) Department of Psychology, 2 Hillhouse Avenue New Haven, CT 06520 USA Abstract equally weighted according to the DSM-IV. For instance, “refusal to maintain body weight at or above minimal lev- els” in anorexia nervosa was judged to be significantly more central than “absence of the period (in women) for more than 3 months of menstrual cycles. ” What would be the bases of clinicians’ weightings of these symptoms? The implications for the current study are two-fold. First, there are clinical implications. If clinicians’ perception of feature centrality deviates from a certain norm (e.g., DSM- IV), we can develop better training programs that address the basis of these misperceptions. Second, there are impli- cations for basic cognitive psychology. Previous studies have demonstrated strong influences of people’s theories about concepts in determining feature centrality (e.g., Ahn, 1998; Rehder & Hastie, 2001; Sloman, Love, & Ahn, 1998). Examining this phenomenon in the domain of mental disor- ders offers an interesting test-bed because the theories that clinicians hold about mental disorders appear to be rather fragile. For one thing, it is a well-known fact that there rarely is any consensus on or clear understanding of the eti- ology of mental disorders. Furthermore, the DSM-IV (APA, 1994) discourages users from applying their own theories by forcing them to go through a checklist of iso- lated symptoms regardless of any potential causal structures underlying these symptoms. Given that the major guideline for mental disorder diagnosis pushes for such an atheoretical stance, it is interesting to examine whether the influence of theory would be as robust as in other domains. In the current study, we examined clincians’ concepts of MDD and Dysthymia. These two mental disorders are good candidates for studying clincians’ theories because they are highly prevalent, and most clinicians are familiar with them (Flanagan & Ahn, 2005). Thus, clinicians’ judgments on these disorders could not be simply attributed to their lack of experiences with these disorders. In what follows, we will first describe how we measured feature centrality in these disorders. Then, we will discuss three potential determinants for feature centrality. What determines which features are more central in concepts? Sloman, Love, and Ahn (1998) examined laypeople’s con- cepts about everyday objects (e.g., chairs and apples) and found that lay theories of these concepts determined feature centrally as much as category validity judgments (i.e., how prevalent features are in a given category) did. The current study examined determinants of feature centrality in 35 clini- cal psychologists, psychiatrists, and clinical social workers’ concepts of Major Depressive Disorder (MDD) and Dysthymic disorder (Dysthymia). Unlike previous findings, we found that category validities were by far the strongest predictor of conceptual centrality in clinicians’ concepts of these mental disorders and their theories about these disorders were only a weak, albeit significant, predictor. We discuss possible reasons for this discrepancy. Keywords: categorization; reasoning; clinical diagnosis; the- ory-use; causal reasoning. Introduction Features in concepts vary in their importance. In the concept of cats that most educated people hold, for instance, the ge- netic structure of a cat would be judged to be much more important than the fact that they meow. That is, we can eas- ily imagine a cat that does not meow, but it is extremely difficult to imagine a cat that does not have “cat DNA”. The current study examines why some features in clini- cians’ concepts of mental disorders are more crucial than others. The domain of mental disorders is particularly inter- esting because the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association [APA], 1994), the official guidelines that clinicians must follow for diagnostic and insurance purposes, explicitly specifies that all symptoms of a given disorder be weighted equally (with only a few exceptions). For instance, there are four symptoms listed as the diagnostic criteria for anorexia nervosa, all of which have to be present in order to be diag- nosed with the disorder. Yet, Kim and Ahn (2002) found that clinical psychologists assign significantly different rat- ings of importance among symptoms that are supposed to be