An interaction between perceived stress and 5HTTLPR genotype in the prediction of stable depressive symptomatology.

A significant amount of research has examined the interaction between a functional polymorphism in the serotonin transporter gene (5HTTLPR) and stressful life events in the prediction of depression and depressive symptomatology. The results of these studies have produced conflicting evidence, with some studies substantiating a significant interaction and others failing to detect a significant interaction. The purpose of the current study was to add to this line of research by testing for an interaction between 5HTTLPR and perceived stress in the prediction of stable depressive symptomatology. Analysis of data from the National Longitudinal Study of Adolescent Health (Add Health) indicates that the association between perceived stress and depression is moderated by 5HTTLPR genotype for females, but not for males. Specifically, females who were homozygous for the short allele were significantly more likely to report symptoms of depression in the face of perceived stress when compared to females who were homozygous or heterozygous for the long allele.