本文发表在 rolia.net 枫下论坛how much one uses, and how one responds to consequences of that use, both negative and positive. Twin studies have repeatedly demonstrated the magnitude of these effects, showing that somewhere between 40 and 60% of the variance for substance use disorder (SUD) is accounted for by shared and non-shared environment (Kendler et al., 2012). Historically, the heaviest focus in this arena has been on drug-specific behavior, in particular, the environment’s role in determining onset of use, the development and maintenance of heavier and/or problematic use, and the creation of rule structures for regulation of access (Clark, 1991; Clayton, 1992). Most fundamentally, onset of use is literally contingent on an adolescent’s environment, as it is concretely dependent upon the availability of the substance to the youth. Proximal availability not only determines ease of access, it also provides cueing, which activates neural circuitry relating to expectancies about use. It may also arouse craving (Bachman et al., 1991; Oetting and Donnermeyer, 1998). Regulating structures, both macrolevel (e.g. laws regulating availability) and proximal (e.g., the implicit rules about use among those who the child interacts with and/or observes on a daily basis) set brakes on inappropriate use, and provide penalties for violation of those regulations.更多精彩文章及讨论，请光临枫下论坛 rolia.net