The present investigation evaluated the Anxiety Sensitivity (AS) taxon using the 16-item Anxiety Sensitivity Index (Reiss, Peterson, Gursky, & McNally, 1986) and its relation with two theoretically relevant cognitive processes associated with panic vulnerability: bodily vigilance and perceived uncontrollability over anxiety-related events. Taxometric analyses of 589 young adults indicated that the latent structure of AS was taxonic with an estimated base rate ranging between 13% and 14%. As predicted, an 8-item ASI Taxon Scale accounted for significant variance above and beyond that accounted for by the full-scale ASI total score in terms of bodily vigilance and perceived controllability of anxiety-related events. Moreover, after accounting for the variance explained by the full-scale ASI total score, the total score for the 8 ASI items not included in the ASI Taxon Scale was associated with significant variance in these same dependent measures, but it was in the opposite direction from that predicted by contemporary panic disorder theory. Dichotomous taxon membership accounted for significant variance above total ASI scores for bodily vigilance but not perceptions of control for anxiety-related events. These findings are discussed in terms of their theoretical implications for the study of AS and panic vulnerability.
Keywords: anxiety sensitivity; taxometrics; anxiety; bodily sensations; perceived control; panic attacks
Anxiety Sensitivity (AS), defined as the fear of anxiety and anxiety-related sensations (Reiss & McNally, 1985), is a traitlike cognitive predisposition that can theoretically increase the risk of panic and other types of anxiety problems. Since the 1980s, there has been a concerted scientific effort toward better understanding the latent structure of the AS construct (see Taylor, 1999, for a review). Whereas earlier theoretical models of the construct posited a unidimensional structure, subsequent factor analytic investigations have suggested that AS is hierarchical (Zinbarg, Mohlman, & Hong, 1999). These findings have helped researchers enhance the level of explanatory precision of AS in models of anxiety vulnerability (Zinbarg, Brown, Barlow, & Rapee, 2001; Zvolensky, Kotov, Antipova, & Schmidt, 2005).
More recently, researchers have begun to explore the latent structure of AS using taxometric procedures. Taxometrics is a branch of applied mathematics that focuses on the classification of entities (Meehl, 1995). It provides a set of statistical procedures that are used to test the latent structure of constructs (Beauchaine, 2003; Cole, 2004; Meehl, 1995, Schmidt, Kotov, & Joiner, 2004; Waller & Meehl, 1998). Although taxometric investigations have been completed for various types of psychopathology (e.g., Beach & Amir, 2003; Gleaves, Lowe, Snow, Green, & Murphy-Eberenz, 2000; Harris, Rice, & Quinsey, 1994; Haslam & Beck, 1994; Lenzenweger, 1999), the application of these analytic methods to anxiety-related constructs, including AS, is a relatively recent development (Bernstein, Zvolensky, Kotov, et al., 2006; Bernstein, Zvolensky, Weems, Stickle, & Leen-Feldner, 2005; Ruscio, Borkovec, & Ruscio, 2001; Ruscio, Ruscio, & Keane, 2002; Taylor, Rabian, & Fedoroff, 1999). This work is important on theoretical grounds in the sense that it can help explicate the extent to which AS (and other anxiety constructs) is best understood from a continuous or categorical perspective. Such knowledge, in turn, ought to help direct research and clinical activities regarding anxiety-relevant vulnerability (broadly), and panic-relevant vulnerability (specifically) in a more effective and efficient manner (Beauchaine, 2003).
Unlike earlier theoretical models positing a dimensional AS latent structure (i.e., an individual difference factor that varies only by degree; Reiss & McNally, 1985), more recent empirical investigations suggest that AS may be taxonic (i. …