Serotonin transporter gene and inhibition of conflicting emotional information

Genetic variation of the serotonin-transporter-linked promoter region has been reported to be associated with susceptibility to mood disorders. However, little is known about the behavioral characteristics that mediate this genetic variation and susceptibility to depression. We examined whether the serotonin-transporter genotype modulates inhibition of facial expressions and emotional words in the emotional 'face-word' Stroop task. Although negative word distractors interfered with the valence identification of positive faces among carriers of two short alleles, positive word distractors interfered with that of negative faces among carriers of one or two long alleles. We discuss a possible role of the reduced inhibitory control over semantic negative information in carriers of two short alleles in the risk of developing depressive mental state.