Despite these limitations, this study reflects the potential scientific contributions that can be made when one of the most salient known environmental risk factors for human psychopathology, child maltreatment, is ascertained accurately and coupled with genetically-informative variables in epidemiologically-defined sampling frames. Official-report maltreatment data is available in every state in the U.S. but is rarely, if ever, used to test hypotheses about genetic and environmental causation for major mental health outcomes. We have demonstrated here an ethically acceptable method for harnessing large-scale official-report maltreatment data in the study of additive effects of genetic and environmental influence on developmental outcome, and encourage replication of this procedure using more specific indices of biological risk. It is also clear from this study that the loss of data incurred by the policy of expunging records after relatively brief intervals of developmental time compromise their power to elucidate the critical role of life events on human development from infancy through adulthood.
