WEDNESDAY, Oct. 5 (HealthDay News) -- Youth carrying two short alleles of 5-HTTLPR are more susceptible to parenting as environmental context, according to a study published online Oct. 4 in Translational Psychiatry.
Benjamin L. Hankin, Ph.D., from the University of Denver, and colleagues investigated a gene-environment interaction (GxE) based on a differential susceptibility hypothesis (DSH) that was hypothesized to influence level of positive affect in youths. Youths' 5-HTTLPR genotype and rearing environment were analyzed in three independent GxE studies, including a total of 1,874 children and adolescents (aged 9 to 15 years). Positive/supportive parenting was analyzed via parent report in study one (307 participants, 54 percent girls), via coded observation of parent-child interactions in the laboratory in study two (197 participants, 58 percent girls), and via self-report in study three (1,370 participants, 53 percent girls).
The investigators found that in all three studies youth who were homozygous for the functional short allele of 5-HTTLPR were more responsive to parenting as environmental context in a "for better and worse" manner. Genetically susceptible youth had low levels of positive affect when they experienced unsupportive, non-positive parenting conditions, and higher levels of positive affect when they experienced supportive and positive parenting conditions.
"The association between positive/supportive parenting and youths' level of positive affect in children and adolescents was significant only among youth carrying two short alleles, but not those carrying a long allele, of 5-HTTLPR. Consequently, 5-HTTLPR may confer susceptibility to environmental context for positive affectivity among the youth," the authors write.