Control adolescents were recruited through a marketing research company to be similar to patients in terms of age, race, sex and zip code of residence (n=185). At initial recruitment controls were not excluded for conduct or substance use disorders. Close age siblings were also invited to participate, as were parents of controls. One hundred and sixty three siblings of controls gave written informed consent, completed diagnostic instruments for CD/AD and provided a DNA sample. Two hundred and sixty three parents of controls (105 fathers and 158 mothers) provided DNA which was genotyped for rs279871.
