Maltreatment places children at risk for psychiatric morbidity, especially conduct problems. However, not all maltreated children develop conduct problems. We tested whether the effect of physical maltreatment on risk for conduct problems was strongest among those who were at high genetic risk for these problems using data from the E-risk Study, a representative cohort of 1,116 5-year-old British twin pairs and their families. Children's conduct problems were ascertained via parent and teacher interviews. Physical maltreatment was ascertained via parent report. Children's genetic risk for conduct problems was estimated as a function of their co-twin's conduct disorder status and the pair's zygosity. The effect of maltreatment on risk for conduct problems was strongest among those at high genetic risk. The experience of maltreatment was associated with an increase of 2% in the probability of a conduct disorder diagnosis among children at low genetic risk for conduct disorder but an increase of 24% among children at high genetic risk. Prediction of behavioral pathology can attain greater accuracy if both pathogenic environments and genetic risk are ascertained. Certain genotypes may promote resistance to trauma. Physically maltreated children whose first-degree relatives engage in antisocial behavior warrant priority for therapeutic intervention.Maltreatment poses severe risks to children's health and development and is increasingly coming to the attention of primary care clinicians and other community professionals Sedlak & Broadhurst, 1996). A major consequence of maltreatment in early childhood is antisocial behavior (Dodge, Bates, & Pettit, 1990;Lansford, Dodge, Pettit, Bates, Crozier, & Kaplow, 2002;Smith & Thornberry, 1995;Widom, 1989;Widom & Maxfield, 2001). Such early-onset antisocial behavior is, in turn, associated with life-long and pervasive mental (Moffitt, Caspi, Harrington, & Milne, 2002), physical (Farrington, 1995), economic (Caspi, Wright, Moffitt, & Silva, 1998), and interpersonal problems that create an enormous public-health burden (Potter & Mercy, 1997).However, not all maltreated children develop conduct problems (Widom, 1997), and some maltreated children exhibit adaptive functioning (Cicchetti, Rogosch, Lynch, & Holt, 1993) that is still evident in adulthood (McGloin & Widom, 2001). Very little systematic evidence is available to explain why children show such marked variation in their response to maltreatment. Such variability would be observed if there were genetically influenced individual differences in susceptibility to environmental experiences like maltreatment, a Address correspondence and reprint requests to: Sara Jaffee, Department of Psychology, University of Pennsylvania, 3720 Walnut Street, Philadelphia, PA 19104; srjaffee@psych.upenn
NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript concept referred to as "gene-environment interaction" (GxE; Kendler & Eaves, 1986;Rutter & Silberg, 2002). The GxE concept is familiar to clinicians as the "host-...