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

AIMS: This study examined how family, peer and school factors are related to different trajectories of adolescent alcohol use at key developmental periods.

DESIGN: 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.

SETTING: Adolescents completed surveys during school hours.

PARTICIPANTS: A total of 808 students in Victoria, Australia.

MEASUREMENTS: 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.

FINDINGS: 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‚Äâ=‚Äâ0.031) and parental attitudes at grade 5 (P‚Äâ=‚Äâ0.003), and age-generalized effects for sibling alcohol use (Ps‚Äâ=‚Äâ0.001, 0.012, 0.033 at grades 5, 7 and 9, respectively) and peer alcohol use (Ps‚Äâ=‚Äâ0.041, <‚Äâ0.001, <‚Äâ0.001 at grades 5, 7 and 9, respectively). Poor parental supervision was associated with steep escalators at grade 9 (P‚Äâ<‚Äâ0.001) but not the other grades. Attachment to parents was unrelated to alcohol trajectories.

CONCLUSIONS: 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.