Although S homozygotyes with negative rearing experiences may be at heightened risk to psychopathology by virtue of low positive affect, our ‘for better and worse' findings also highlight the plasticity of 5-HTTLPR as a susceptibility gene. Youth carrying two short alleles exhibited higher levels of positive affect when reared by positive/supportive caregivers. Various empirically supported parenting treatments and preventions have proven efficacious at reducing psychopathology by augmenting positive, supporting parenting practices.58, 59 Findings from the present studies suggest that the main effect of parenting interventions may be significantly enhanced for genetically susceptible youth carrying plasticity genes, such as 5-HTTLPR. Likewise, some genetically susceptible youth who have experienced consistent positive/supportive parenting may be resilient and protected against developing psychopathology when faced with other negative environmental stressors, because such youth may be able to upregulate positive emotion to counteract deleterious consequences and negative emotion resulting from stressful events.60, 61, 62 In sum, and as highlighted by the DSH, susceptibility genes such as 5-HTTLPR may not bestow vulnerability to psychopathology per se, but instead confer enhanced reactivity and responsivity to environmental contexts, such as developmentally salient influences of parenting.63
