Genetic and environmental predictors of early alcohol use.

Background: The goal of the current investigation was to examine genetic and environmental predictors of early alcohol use, a potent predictor of later alcohol dependence.

Methods: This study represents an add-on project to an investigation examining the efficacy of an intervention for maltreated children entering out-of-home care. Predictors of early alcohol use include the following: maltreatment, family loading for alcohol or substance-use disorders, and serotonin transporter genotype (5-HTTLPR; locus SLC6A4). Participants included 127 subjects: 76 maltreated children and 51 demographically matched community controls.

Results: At follow-up, 29% of the maltreated children reported alcohol use, a rate more than seven times the rate observed in controls. Maltreated children also drank alcohol, on average, more than 2 years earlier than controls (11.2 vs. 13.5 years). Early alcohol use was predicted by maltreatment, 5-HTTLPR, and a gene by environment interaction, with increased risk for early alcohol use associated with the s-allele. Psychopathology at baseline, severity of maltreatment, and poor mother-child relations also predicted early alcohol use.

Conclusions: Maltreated children are at high risk for psychiatric, alcohol, and substance abuse problems. Examination of genetic and environmental risk and protective factors can help identify those who are most vulnerable and help guide prevention and intervention efforts.