24 JOURNAL OF STUDIES ON ALCOHOL AND DRUGS / JANUARY 2014 Predictors of Subgroups Based on Maximum Drinks per Occasion Over Six Years for 833 Adolescents and Young

ABSTRACT. Objective: A person’s pattern of heavier drinking often changes over time, especially during the early drinking years, and refl ects complex relationships among a wide range of characteristics. Optimal understanding of the predictors of drinking during times of change might come from studies of trajectories of alcohol intake rather than cross-sectional evaluations. Method: The patterns of maximum drinks per oc-casion were evaluated every 2 years between the average ages of 18 and 24 years for 833 subjects from the Collaborative Study on the Genetics of Alcoholism. Latent class growth analysis identifi ed latent classes for the trajectories of maximum drinks, and then logistic regression analyses highlighted variables that best predicted class membership. Results: Four latent classes were found, including Class 1 (69%), with about 5 maximum drinks per occasion across time; Class 2 (15%), with about 9 drinks at baseline that increased to 18 across time; Class 3 (10%), who began with a maximum of 18 drinks per occasion but decreased to 9 ove