then submitted to EFA and CFA. Lastly, item response theory (IRT) analysis was performed to obtain the threshold and discrimination parameter of each item and to derive the TLI. The items of the TLI, along with scoring criteria, informant, and reference source, are shown in the Appendix. As is shown, the TLI items are indicative of biopsychological self-regulation. Besides externalizing behaviors, the items pertain to thoughts about death during stress (#7), self-harm (#31), biting fingernails (#25), poor sleep (#32, 33), irregular appetite (#36), somatic distress (#29, 30), and adapting to new situations (#42, 43, 44). The diversity of these characteristics notwithstanding, the TLI has internal reliability exceeding .90 (Vanyukov et al., 2009). Moreover, it predicts SUD between childhood and adulthood (Kirisci et al., 2009) and all SUD categories in adults (Ridenour, Kirisci, Tarter, & Vanyukov, 2011).
