Testing alternative cascades from internalizing and externalizing symptoms to adolescent alcohol use and alcohol use disorder through co-occurring symptoms and peer delinquency.

Given the equivocal literature on the relationship between internalizing symptoms and early adolescent alcohol use (AU) and AU disorder (AUD), the present study took a developmental perspective to understand how internalizing and externalizing symptoms may operate together in the etiology of AU and AUD. We pit the delayed onset and rapid escalation hypothesis (Hussong et al., 2011) against a synthesis of the dual failure model and the stable co-occurring hypothesis (Capaldi, 1992; Colder et al., 2013, 2018) to test competing developmental pathways to adolescent AU and AUD involving problem behavior, peer delinquency, and early initiation of AU. A latent transactional and mediational framework was used to test pathways to AUD spanning developmental periods before AU initiation (Mage = 11) to early and high risk for AUD (Mage = 14-15 and Mage = 17-18). The results supported three pathways to AUD. The first started with "pure" externalizing symptoms in early childhood and involved multiple mediators, including the subsequent development of co-occurring symptoms and peer delinquency. The second pathway involved stable co-occurring symptoms. Interestingly, chronically elevated pure internalizing symptoms did not figure prominently in pathways to AUD. Selection and socialization effects between early AU and peer delinquency constituted a third pathway.