Explanation Effects Override Formal Category Definitions In Clinical Experts' Diagnostic Judgments.

Explanation Effects Override Formal Category Definitions In Clinical Experts’ Diagnostic Judgments Nancy S. Kim, Thao P. Nguyen, and Daniel J. Paulus (n.kim@neu.edu, nguyen.tha@husky.neu.edu, d.paulus@neu.edu) Department of Psychology, 125 Nightingale Hall, Northeastern University, 360 Huntington Ave. Boston, MA 02115 USA Abstract Having a plausible life-event explanation for a person’s disordered symptoms leads clinicians to judge those symptoms to be less abnormal than if their cause was unknown (Ahn et al., 2003). Yet the American Psychiatric Association’s official Diagnostic and Statistical Manual of Mental Disorders formally states that only bereavement- related life events should exclude a client from a diagnosis of depression, and this bereavement exclusion criterion is slated to be eliminated altogether from the next edition (under development) of the manual. We asked whether clinicians make diagnoses in the context of life-event explanations in direct opposition to these formal prescriptive definitions. We asked clinical psychologists to give diagnostic and other clinical judgments for realistic case study vignettes including a bereavement event, negative non-bereavement event, neutral event, or no event. Both bereavement and non-bereavement life events normalized clinicians’ perceptions of depression, indicating a clear departure from both the current and proposed DSM. Keywords: explanation; categorization; diagnosis; reasoning; judgment; expertise Introduction Do clinicians interpret symptoms within the explanatory context of life events even when their official diagnostic system explicitly specifies that they should not? Past research has shown that students and clinical psychologists systematically take causal life-event context into account when judging the psychological abnormality and need-for- treatment of artificial, hypothetical case vignettes (e.g., Ahn et al., 2003; Kim & LoSavio, 2009; Meehl, 1973). For example, people were shown the hypothetical case of a person who has insomnia, trouble remembering the names of objects, and episodes of extreme anxiety. Those study participants who did not receive an explanation for why these symptoms had occurred rated them as quite abnormal. In contrast, those who were given a relatively plausible explanation for what precipitated those symptoms (e.g., workload stress caused the frequent insomnia, etc.) rated them as significantly more normal and less in need of psychological treatment. Life event causes normalized symptoms more than biological causes (Ahn et al., 2003), and externally-controlled life events reduced perceptions of the need for treatment more than internally-controlled life events (Kim & LoSavio, 2009). However, in past work, case vignettes were synthesized from multiple unrelated disorders, and thus did not bear a clear resemblance to any one real disorder. An important question therefore remains regarding the degree to which explanatory context would affect diagnostic and clinical reasoning for “real” disorders. Formal category definitions for psychological abnormality have already been established in the Diagnostic and Statistical Manual of Mental Disorders (henceforth DSM-IV-TR; 4 th Edition, American Psychiatric Association, 2000), and are widely known and used by licensed clinical practitioners. 1 In particular, the strength of the influence of explanations on clinical judgments is unknown for cases wherein taking explanatory life-event context into account would run directly contrary to DSM specifications. To give an illustrative example, suppose that a person has been showing depressive symptoms following a personally catastrophic financial loss. Would expert clinicians judge that person to be any less disordered than someone showing the same symptoms following no particularly noteworthy event? The diagnostic criteria for depression in the current DSM-IV-TR and the February 2010 in-progress proposal for the upcoming 5 th edition of the manual (DSM-5; APA, 2010; http://www.dsm5.org) do not distinguish between these two cases; the formal recommendation of the American Psychiatric Association is to treat both cases identically in diagnosis, ignoring contextual differences. This deliberate removal of explanatory context is characteristic of the diagnostic criteria for the vast majority of disorders listed in the manual (Horwitz & Wakefield, 2007). On the flip side, consider the introduction sections of the very same DSM-IV-TR and proposed DSM-5 (Stein et al., 2010), in which the intended guiding philosophy of the manuals is described. The introduction sections of both versions explicitly state that significant life events should be taken into consideration when identifying a set of behaviors that correspond to a mental disorder, recognizing that psychological distress reflects relatively normal mental health under stressful circumstances (Horwitz, 2007). This apparent internal ambivalence (between intended guiding philosophy and actual diagnostic criteria) in the DSM-IV-TR and the proposed DSM-5 is illustrative of a longstanding ongoing debate regarding the proper role of explanatory life events in assessment. In clinical science, the debate has The disorders and diagnostic criteria contained in the DSM system are determined by a “task force” comprised of a large set of widely acknowledged experts in the field. The manual serves as the core basis for communication among researchers and clinicians in a number of countries, and is considered the authoritative basis for psychiatric diagnoses by health insurance companies in the U.S., the country from which our participant sample was drawn.