variable, because this phenotype and accompanying odds ratios may also be of interest. Case status was defined by the endorsement of ≥3 of the 15 DSM-IV CD criteria under Criterion A, without assessing the requirement of clustering of different symptoms within a 12-month time period. Furthermore, we did not use Criterions B and C (significant clinical impairment and absence of Antisocial Personality Disorder) in defining cases. We refer to this phenotype as CD case status throughout this paper, although we note that full diagnostic criteria were not applied. Controls were defined as those who endorsed fewer than three symptoms for DSM-IV CD. A total of 872 subjects met these criteria for CD case status, and there were 3091 controls. The mean age of the CD cases was 37.32 years (s.d. = 8.86; range 18–74 years). The mean age of the CD controls was 39.63 years (s.d. = 9.13; range 18–77 years).
