“…The annual prevalence of any NMUPD (i.e., stimulants, opioids, sedatives, or tranquilizers) among U.S. college students increased from 8.3% in 1996 to 14.6% in 2006 while the prevalence of marijuana declined over this same time period (Johnston et al, 2007). The nonmedical use of prescription stimulants is more prevalent among U.S. college undergraduate students than their same-age peers not attending college while the nonmedical use of prescription opioids is more prevalent among young adults not attending college (e.g., Herman-Stahl et al 2007;Johnston et al, 2007;SAMHSA, 2005). There is evidence that the nonmedical use of prescription stimulants and opioids is more prevalent among particular subgroups of U.S. college students and types of colleges (e.g., Johnston et al, 2007;McCabe et al, 2005aMcCabe et al, , 2005b.…”