Adult siblings (over 18) were assessed utilizing the Diagnostic Interview Schedule (DIS) (Robins et al., 1981). Similar to the DISC, the study began with the III-R version and a locally modified version IV (which assessed III-R diagnoses) was used once available. One CD III-R criterion was removed from the DIS-III-R at the beginning of the study (forced sex) and in accordance with the DSM-III-R, breaking and entering was not included as a CD criterion under the antisocial personality disorder diagnosis; thus adult siblings assessed with the version III-R of the DIS (n=41; 36 patient siblings and 5 control siblings) were not asked about breaking and entering or forced sex. Those siblings were excluded from analyses utilizing CD symptom count. Of those 41 adult siblings, 21 had determinable CD diagnoses (defined here as at least three lifetime CD DSM-III-R criteria) because they had scores of 0 or ≥ 3 (i.e. the missing two items whether endorsed or not would not make those with a score of 0 meet the symptom count threshold). Adult siblings assessed with version III-R of the DIS with determinable CD diagnoses (21/41) were included in analyses utilizing CD diagnosis.
