Piecewise Growth Mixture Modeling of Adolescent Alcohol Use Data

Abstract
This article addresses issues of heterogeneity in multiple-stage development as it corresponds to qualitatively different development in alcohol use during adolescence. Using a piecewise growth mixture modeling methodology proposed by Muthén (in press), a 2-piece linear growth model capturing growth trajectories in adolescent alcohol use during the transition from middle school (ages 11 to 13) to high school (ages 14 to 17; N = 81) was examined. It was hypothesized that 2 stages of alcohol use development with varying trajectories would exist in these data, the 1st corresponding to development during middle school (Growth Rate 1), followed by a 2nd stage of continuing growth during high school (Growth Rate 2). Results suggested the tenability of the 2-piece linear development in alcohol use and the emergence of 2 latent classes with individually varying transition points. Class 1 showed linear increases only during high school, whereas Class 2 showed a continued, linear growth throughout the middle and hi...