Predicting steep escalations in alcohol use over the teenage years: age-related variations in key social influences

<b>Aims</b><br />This study examined how family, peer and school factors are related to different trajectories of adolescent alcohol use at key developmental periods.<br /><br /><b>Design</b><br />Latent class growth analysis was used to identify trajectories based on five waves of data (from grade 6, age 12 to grade 11, age 17), with predictors at grades 5, 7 and 9 included as covariates.<br /><br /><b>Setting</b><br />Adolescents completed surveys during school hours.<br /><br /><b>Participants</b><br />A total of 808 students in Victoria, Australia.<br /><br /><b>Measurements</b><br />Alcohol use trajectories were based on self-reports of 30-day frequency of alcohol use. Predictors included sibling alcohol use, attachment to parents, parental supervision, parental attitudes favourable to adolescent alcohol use, peer alcohol use and school commitment.<br /><br /><b>Findings</b><br />A total of 8.2% showed steep escalation in alcohol use. Relative to non-users, steep escalators were predicted by age-specific effects for low school commitment at grade 7 (P = 0.031) and parental attitudes at grade 5 (P = 0.003), and age-generalized effects for sibling alcohol use (Ps = 0.001, 0.012, 0.033 at grades 5, 7 and 9, respectively) and peer alcohol use (Ps = 0.041, < 0.001, < 0.001 at grades 5, 7 and 9, respectively). Poor parental supervision was associated with steep escalators at grade 9 (P < 0.001) but not the other grades. Attachment to parents was unrelated to alcohol trajectories.<br /><br /><b>Conclusions</b><br />Parental disapproval of alcohol use before transition to high school, low school commitment at transition to high school, and sibling and peer alcohol use during adolescence are associated with a higher risk of steep escalations in alcohol use.