The requirement for a low total number of variables prompted a decision to index inherited liability to antisocial development using all adult diagnoses known to be associated with offspring antisocial outcome: these include not only antisocial personality disorder (ASPD) (a severe form of antisocial behavior in adults) but also alcohol and/or substance dependence, which are more common predictors of offspring antisocial risk. Thus, in COGA, familial liability was parameterized by ascertaining the closest adult relative with either antisocial personality disorder, alcohol dependence, or drug dependence ascertained by a) the Semi-Structured Assessment for Genetics of Alcoholism (for parents, i.e. first degree adult relatives) and b) the Family Interview for Genetic Studies (FIGS) (for second or third degree relatives). Each child was consequently scored as having 1 of 2 levels of genetic liability: 1—closest relative with any of these disorders is a first degree relative; 2—closest relative with any of these disorders is a second degree or higher relative (over 96% of the children in the sample had either a 1st or 2nd degree adult relative with an antisocial disorder as operationalized here).
