Despite these challenges, pursuit of an internalizing pathway is of keen interest in the study of SUDs for several reasons. First, several studies report prospective prediction of adolescent alcohol involvement from childhood internalizing problems. For example, studies by Zucker and colleagues (Zucker, Chermack, & Curran, 2000) of high-risk youth show effects of internalizing symptoms in children as young as ages 2–5 on substance use in early adolescence. Moreover, community based samples also find that early indicators of internalizing symptoms in early- to mid-childhood (e.g., symptoms of anxiety and depression and inhibited temperament) predict substance involvement into late-adolescence and early adulthood (Caspi et al., 1996; Caspi, Moffitt, Newman, & Silva, 1996; Kellam, Ensminger & Simon, 1980).
