Variations in the serotonin-transporter gene are associated with attention bias patterns to positive and negative emotion faces

Both attention biases to threat and a serotonin-transporter gene polymorphism (5-HTTLPR) have been linked to heightened neural activation to threat and the emergence of anxiety. The short allele of 5-HTTLPR may act via its effect on neurotransmitter availability, while attention biases shape broad patterns of cognitive processing. We examined individual differences in attention bias to emotion faces as a function of 5-HTTLPR genotype. Adolescents (N = 117) were classified for presumed SLC6A4 expression based on 5-HTTLPR-low (SS, SL_G, or L_GL_G), intermediate (SL_A or L_AL_G), or high (L_AL_A). Participants completed the dot-probe task, measuring attention biases toward or away from angry and happy faces. Biases for angry faces increased with the genotype-predicted neurotransmission levels (low > intermediate > high). The reverse pattern was evident for happy faces. The data indicate a linear relation between 5-HTTLPR allelic status and attention biases to emotion, demonstrating a genetic mechanism for biased attention using ecologically valid stimuli that target socioemotional adaptation.