Frequent risk behaviors (i.e., alcohol use, drunkenness, smoking, and cannabis use) were treated as ordinal variables. For presenting the trajectories in one figure, we summed the estimated probabilities for all response categories. As postmodeling refinement, the mean of the slope of the cannabis trajectory in the youngest cohort was freely estimated, as it was shown to be different from the rest of the cohorts. Gender effects were analyzed as correlations between sex and intercepts, slopes, and quadratic terms.
