Developmental Trajectories of Substance Use in Adolescence: Differences and Predictors
We applied a combination of variable-centred and person-centred approaches to the analysis of data from a longitudinal study of substance use in adolescence (ages 12-18). Regression models were specified to permit a distinction between chronic differences and changes in selected risk factors. Both chronic differences and changes in risk factors were found to predict differences in use at ages 15 and 18. However, the obtained regression models were found to be least applicable to adolescents deviating most from the normative longitudinal pattern, that is, adolescents exhibiting chronically low levels of use, adolescents exhibiting chronically high levels of use, and adolescents exhibiting a sharp increase in use between the ages of 15 and 18. Furthermore, risk factors linked to small or moderate deviations and those linked to more extreme deviations from the normative pattern were only partly the same.