Purpose: The purpose of the current study was to investigate the influence of externalizing behaviors on substance initiation trajectories among rural adolescents over a 42-month period.
Methods: Data were obtained from 198 rural adolescents (105 boys, 93 girls) who were participating in a longitudinal study. At the baseline assessment, subjects were on average 12.3 years of age.
Results: Controlling for gender, higher baseline levels of externalizing were associated with a greater number of substances initiated over time. The initiation trajectory was curvilinear. Girls, compared with boys, reported a lower number of substances initiated at baseline, a greater linear growth trajectory, and a deceleration of growth over time.
Conclusions: The influence of adolescent externalizing behaviors on baseline levels and growth trajectories of substance initiation and the utility of latent growth curve modeling in the study of longitudinal change are discussed.