Serotonin transporter polymorphism interacts with childhood adversity to predict aspects of impulsivity.

The serotonin transporter polymorphism has been linked--often in interaction with environmental adversity--to a variety of outcomes, including affective disorders. This polymorphism is widely viewed as relating to anxiety traits. A different view is that it relates instead to impulsivity (vs. control) in reacting to emotions. In a test of the latter view, 303 students were genotyped on this polymorphism and completed self-reports bearing on impulsive reactions to emotions (including both negative and positive emotions in separate measures), impulsive tendencies that do not stem from emotions, and childhood adversity. The impulsivity measures reflected three latent variables: pervasive influence of feelings, feelings (including positive feelings) triggering action, and failure to carry through on intentions (with no mention of emotion). Interactions between genotype and adversity emerged for both emotion-related aspects of impulsivity. Theoretical implications of the findings are discussed.