In an effort to elucidate new factors that may contribute to developmental psychopathology, the current study examined whether accelerated epigenetic aging at birth related to children's differential susceptibility to the effects of aversive parenting on early emerging mental health risk. Using data from a multiethnic birth cohort, the interaction between Horvath's methylation age in umbilical cord blood and hostile parenting behaviors was examined in relation to perceptions of infant's temperament at 6 months and to children's psychological symptoms at 3 years in 154 families. Results broadly revealed that children with higher levels of accelerated methylation aging evinced more unpredictable temperaments and more psychological symptoms if their mothers reported more hostile parenting, but showed fewer difficulties if mothers engaged in less hostile parenting; children with lower levels of accelerated methylation age did not show associations between hostility and temperament or psychological symptoms. Effects were not accounted for by gestational age at birth, demographic factors, or the distribution of cell subtypes. These findings suggest that accelerated epigenetic age may function as a form of differential susceptibility, signaling increased risk for psychopathology in more aversive contexts but decreased risk in less aversive early environments. Taken together, they point to a novel biological process to consider within risk for psychopathology.
