Genetic and environmental predictors of latent trajectories of alcohol use from adolescence to adulthood: a male twin study.

BACKGROUND

Adolescence is characterized by higher levels of novelty-seeking and risk-taking behavior, including initiation of alcohol use. Also, there is considerable heterogeneity in the change and continuity of alcohol use over time, which emphasizes the need to examine factors predicting alcohol use and the patterns of use over time.

METHODS

Retrospective data on average monthly alcohol use and risk and protective factors were obtained through interviews and questionnaires in 1,560 adult male twins. Latent class growth analysis in Mplus was performed on data of alcohol use over ages 15 to 36. Second, logistic regression analyses were used to associate risk and protective characteristics with membership in distinct latent trajectories of alcohol use.

RESULTS

Six trajectories of alcohol use were identified, varying in the level of alcohol use, the rate of change in use in early adolescence and the persistence of use into adulthood. Genetic risk of externalizing disorder and peer deviance showed the greatest risks for unfavorable alcohol trajectories with higher levels of use and higher rates of early increase in use. Parental monitoring and involvement in social activities showed protective effects. Involvement in religious activities was strongly associated with reduced persistence of high-level drinking in univariate but not multivariate regression analyses.

CONCLUSIONS

Risk and protective factors impacted differentially on level of alcohol use, rate of increase in use during adolescence, and persistence of heavy alcohol use over time. Insight into the different ways in which predictors impact on alcohol use is relevant for the development of new intervention strategies. For this purpose, causality of the associations should be further examined.