We suggested above that one of the promises of gene × intervention interaction studies was the potential for the use of genetic information to inform who would be best served by a particular preventive intervention. Although this may be the case in the context of selective or indicated preventive interventions, it is less applicable to universal preventive intervention trials like ours where the focus is on improving the family and school environment for all children. Moreover, genetic screening on a universal level would prove logistically and economically infeasible. It would also raise ethical issues as their potential for the use of one’s genetic profile to deny them intervention or treatment.
