Background:A functional polymorphism (5-HTTLPR, rs4795541) in the serotonin transporter (SLC6A4) gene has been shown as an important candidate for several psychiatric and behavioral traits.Objective:The objective of this study was to examine the possible interaction of this polymorphism with physical neglect in childhood on the presentation of anxiety traits and hazardous alcohol consumption in young Colombian subjects.Methods:272 young adults (mean age: 21.3 years) were evaluated with the Childhood Trauma Questionnaire, the Zung Self-rating Anxiety Scale, the Big Five Inventory, the Cohen’s Perceived Stress Scale, the Alcohol, Smoking, Substance Involvement Screening Test and the Alcohol Use Disorders Identification Test. Genotyping for the 5-HTTLPR polymorphism was carried out using conventional PCR. A linear regression model, corrected by age and gender, was used.Results:We found that individuals with the L/L genotype showed higher scores on physical neglect (p=0.0047), anxiety symptoms (p=0.028), neuroticism (p=0.019) and perceived stress (p=0.035). L/L genotype was a risk factor for hazardous alcohol use in young adults (OR=3.06,p=0.0003). No GxE interactions were observed in our data.Conclusion:Our results provide novel evidence for the role of a functional polymorphism in theSLC6A4gene on the relationship of childhood trauma, anxiety-related traits and risky consumption of alcohol.