title: 5-HTTLPR S-allele: a genetic plasticity factor regarding the effects of life events on personality?
abstract: The S-allele of the 5-HTTLPR has been identified as a genetic vulnerability factor, being associated with an increased risk for affective disorders and/or maladaptive traits (e.g. neuroticism), especially after exposition to negative life-events (LEs). Alternatively, it has been hypothesized that this genetic risk factor might constitute a genetic plasticity factor. That is, S-allele carriers are not only vulnerable to the negative effects of a preponderance of stressful LEs but also disproportionally benefit from a preponderance of positive environmental influences. We tested this hypothesis in 357 subjects who were genotyped for the 5-HTTLPR and provided self-reports of neuroticism, life-satisfaction and LEs. Results showed a relatively increased number of positive LEss to be associated with reduced neuroticism (men: β = -0.501, P < 0.05, women: β = -0.369, P < 0.005) and increased life satisfaction (β = 0.494, P < 0.001) within SS-homozygotes. Within SL-heterozygotes, similar tendencies were found. No associations were detected in LL-homozygotes. Extreme Group comparisons revealed a genotype × LE interaction (F(2,198)  = 5.593, P < 0.005), with SS-homozygotes having experienced predominantly positive LEs exhibiting reduced neuroticism (women: F(1,34)  = 4.764, P < 0.05; men: F(1,17)  = 2.092, P = 0.17), and increased life satisfaction (F(1,53)  = 4.057, P < 0.05), as compared to LL-homozygotes having experienced predominantly positive LEs. Our data support the idea that the S-allele of the 5-HTTLPR is associated with an overall increased reactivity to environmental influences, be they positive or negative in nature. These findings constitute a promising add-on to earlier data and support the plasticity hypothesis.
authors.affiliation: Personality Psychology and Individual Differences, Department of Psychology, Justus-Liebig-University Giessen, Giessen, Germany. yvonne.kuepper@psychol.uni-giessen.de
authors.forename: Y
authors.initials: Y
authors.lastname: Kuepper
authors.forename: C
authors.initials: C
authors.lastname: Wielpuetz
authors.forename: N
authors.initials: N
authors.lastname: Alexander
authors.forename: E
authors.initials: E
authors.lastname: Mueller
authors.forename: P
authors.initials: P
authors.lastname: Grant
authors.forename: J
authors.initials: J
authors.lastname: Hennig
mesh_terms: D000328:Adult; D000483:Alleles; D004777:Environment; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D006801:Humans; D008016:Life Change Events; D008297:Male; D019964:Mood Disorders / Q000453:epidemiology / Q000235:genetics*; D009473:Neuronal Plasticity / Q000235:genetics*; D010551:Personality / Q000235:genetics*; D012307:Risk Factors; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics*; D055815:Young Adult
chemical_list: C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins