This internalizing pathway consists of an ongoing set of interactions between risk, protective (serving to decrease risk), and vulnerability (serving to increase risk) factors that lead to SUDs. The core of this model is a set of predictions about how risk for Negative Affect SUDs manifests differently at varying ages. These predictions may reflect mediated associations among risk indicators over time but are perhaps better conceptualized as the heterotypic continuity of Negative Affect SUDs. Within the Developmental Psychopathology framework, heterotypic continuity occurs when a single underlying construct is expressed in varying forms across development (Costello, Foley, & Angold, 2006). Evidence for heterotypic continuity in the internalizing pathway to SUDs comes from Costello et al. (2003) who found relatively greater evidence for heterotypic continuity among internalizing disorders and SUDs than among other forms of adolescence disorder. In articulating the potential markers or expressions of Negative Affect SUDs over development below, we emphasize what may be unique indicators of Negative Affect SUDs rather than indicators of SUDs more generally (see Figure 1).
