Variation in the serotonin transporter polymorphism (5-HTTLPR) and inertia of negative and positive emotions in daily life

Abstract

An important element of understanding the genotype-phenotype link in psychiatric disorders lies in identifying the psychological mechanisms through which genetic variation impacts mental health. Here we examined whether emotional inertia, the tendency for a person's emotions to carry over from 1 moment to the next and a prospective predictor of the development of depression, is associated with a known genetic risk factor for emotional dysregulation, a polymorphism in the serotonin transporter gene (5-HTTLPR). Two hundred thirty-six adolescents recorded their positive and negative emotions in daily life 9 times a day for 6 consecutive days using smartphones, completed a depression questionnaire, and were genotyped for the 5-HTTLPR polymorphism. Carriers of the short 5-HTTLPR were characterized by higher inertia for negative emotions, even after controlling for depressive symptoms. These findings suggest a possible psychological pathway how the serotonin transporter gene contributes to risk for depression.