The Serotonin Transporter Polymorphism (5-HTTLPR): Allelic Variation and Links with Depressive Symptoms

Noreen Goldman, Princeton University
Dana A. Glei, University of California, Berkeley
Yu-Hsuan Lin, Bureau of Health Promotion, Taiwan
Maxine Weinstein, Georgetown University

We use data from a nationally representative sample of older adults in Taiwan to explore variation in the serotonin transporter polymorphism (5-HTTLPR) and to examine interactions among sex, stressful experience and 5-HTTLPR genotype on depressive symptoms. The Taiwan sample comprises a much higher frequency of the S/S genotype and a lower frequency of the L/L genotype than Western samples. Nearly 9% carry an XL allele, an allele rarely reported in the literature. Our findings are consistent with research demonstrating that the effects of the 5-HTTLPR polymorphism are moderated by exposure to stressful experience. We find a positive relationship between depressive symptoms and both lifetime exposure to trauma and major life events in the previous year for persons with the S/S or S/L genotypes, but not for those with the L/L genotype or at least one XL allele. This gene-environment interaction is more notable among females than males.