Using the same data that will be analyzed in this study, we have previously shown that changes in impulsivity correspond to changes in alcohol problems (Littlefield et al., 2009). However, those analyses were based on a variable-centered approach (i.e., latent growth curve analysis) that precluded person-centered inferences based upon specific patterns of developmental courses of impulsivity. That is, these prior analyses demonstrated a strong relation between changes in impulsivity and changes in drinking but at a fairly global level. If there are different trajectories that vary in their basic form beyond their intercept and simple slope, such parallel, bivariate growth models will fail to resolve this potentially important source of developmental differences. An important next step is to characterize developmental patterns of stability and change in impulsivity to further explore individual differences in impulsivity development and to facilitate the further identification of factors relevant to the developmental course of impulsivity. Thus, the current project has three goals: (i) empirically characterize patterns of developmental trajectories of impulsivity; (ii) examine differences in impulsivity development among the identified trajectory groups; (iii) test the utility of the trajectory groups by exploring patterns of the dynamic covariates of alcohol use and related outcomes.
