“…Based on the URS, the parallel shift of classes with respect to criterion endorsement probabilities indicates that classes differ in terms of quantity (i.e., severity), rather than quality (i.e., patterns). This is in line with previous LCA studies on alcohol (Bucholz et al, 1996;Kuo, Aggen, Prescott, Kendler, & Neale, 2008;Muthén, 2006) and other substance use disorders (Agrawal, Lynskey, Madden, Bucholz, & Heath, 2007;Chung & Martin, 2005;Grant et al, 2006). Based on the RS, however, a qualitative interaction between abuse, dependence and class membership emerged.…”