... For the assessment of fear of anxiety-related symptoms, six included studies used the Anxiety Sensitivity Index (ASI; Reiss et al., 1986) or its modified versions (ASI-Revised, Taylor & Cox, 1998;ASI-3, Taylor et al., 2007) in adult populations (see "Appendix D," studies 1-5, 11). The ASI and its modified versions have strong psychometric properties, including internal consistency, test-retest reliability, criterion validity, convergent, and discriminant validity (Allan et al., 2014;Dehon et al., 2005;Reiss et al., 1986;Rifkin et al., 2015;Rodriguez et al., 2004;Taylor et al., 2007;Vujanovic et al., 2007). Although the Anxiety Sensitivity Index is often used as a unidimensional measure (Asmundson et al., 2011), previous studies have found multidimensional latent structure, identifying three, lower-order factors (i.e., physical, social, and cognitive domains), which load onto a single, higher-order, general factor (Asmundson et al., 2011;Calamari et al., 2008;Dehon et al., 2005;Farris et al., 2015;Taylor et al., 2007;Vujanovic et al., 2007;Walsh et al., 2004). ...