title: Differential effects of 5-HTTLPR genotypes on inhibition of negative emotional information following acute stress exposure and tryptophan challenge.
abstract: Previous data suggest that a polymorphism at the serotonin (5-HT) transporter gene (5-HTTLPR) may influence stress resilience and stress-related depression symptoms due to interactions between brain 5-HT dysfunction and stress exposure. Although attentional bias for emotional information has been reliably observed in depression, the interaction between 5-HT transporter-linked promoter region (5-HTTLPR), brain 5-HT vulnerability, and acute stress on affective information processing has not yet been investigated. This study examines the effects of tryptophan (TRP) augmentation (indicating 5-HT manipulation) on inhibition of negative emotional information under stress in mainly female S'/S'- vs L'/L'-allele carriers. A total of 15 female homozygotic short-allele 5-HTTLPR (S'/S'=S/S, S/L(G), L(G)/L(G)) and 13 female homozygotic long-allele 5-HTTLPR (L'/L'=L(A)/L(A)) subjects were tested for mood and inhibition of emotional information in a double-blind, placebo-controlled design before and after stress exposure following TRP manipulation. Stress exposure significantly impaired inhibition of negative affective information only in S'/S' carriers, whereas L'/L' carriers even showed increased inhibition of negative information. The S'/S' allele 5-HTTLPR genotype increases cognitive-attentional bias for negative emotional information under acute stress. As this bias is an important component of depression, this may be a mediating mechanism making S'/S'-allele carriers more vulnerability for stress-induced depression symptoms. Moreover, current data suggest that L'/L'-allele genotypes are more resilient, even increasing cognitive emotional (inhibitory) control after stress.
authors.affiliation: Faculty of Psychology and Neuroscience, Department of Neuropsychology and Psychopharmacology, Universiteitssingel, Maastricht, The Netherlands. r.markus@psychology.unimaas.nl
authors.forename: C Rob
authors.initials: CR
authors.lastname: Markus
authors.forename: Rudi
authors.initials: R
authors.lastname: De Raedt
mesh_terms: D000483:Alleles; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004644:Emotions / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005838:Genotype; D006801:Humans; D007266:Inhibition, Psychological; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D013315:Stress, Psychological / Q000139:chemically induced / Q000235:genetics* / Q000523:psychology; D011795:Surveys and Questionnaires; D013997:Time Factors; D014364:Tryptophan / Q000494:pharmacology* / Q000633:toxicity
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; D014364:Tryptophan