Recent studies have begun to yield evidence of gene-gene and gene-environment interactions underlying inter-individual variability in stress responses. Findings include a monoamine oxidase A (MAOA)-COMT interaction that affects endocrine responses to a psychological challenge task58, a 5-HTTLPR-COMT-stressful life events interaction that affects the risk for depression59, and a COMT-5-HTTLPR interaction that affects limbic reactivity to unpleasant stimuli in healthy subjects60. Kaufman and collaborators reported gene-environment interactions that influence the risk for depression in maltreated children. Social support seems to mitigate the effects of the short allele of 5-HTTLPR61, and the 5-HTTLPR and BDNF Val66Met genotypes interact with stressful life events to predict risk for depression62,63.
