Objectives: Polymorphisms of the serotonin transporter (SERT) gene have been shown to influence the risk for depression. The goal of this study was to investigate a possible effect of SERT polymorphisms on severity and course of depression symptoms in a community sample of adolescents.
Methods: Community-dwelling adolescents (n=192) ages 13-17 years, who were at risk for depression, were followed for a period of 6 months. Subjects donated a saliva sample for genotyping of the 5-HTTLPR and STin2 VNTR polymorphisms of SERT.
Results: We found no associations between SERT genotype and severity of depressive symptoms at baseline. Depression symptom severity markedly decreased over time. For 5-HTTLPR, we observed a significant interaction between time and genotype, indicating the possibility that heterozygote genotype carriers (s/l) might experience a greater reduction in depression symptoms over time compared with adolescents with the 5-HTTLPR l/l genotype.
Conclusions: Our study shows that for most community-dwelling adolescents, depressive symptoms decrease over time. A possible interaction effect of time and SERT genotype will require confirmation in larger studies.