In addition, youth with CD are likely to have a number of comorbid disorders (i.e. depression, ADHD, non-alcohol substance use disorders) and CD has been linked to underlying traits (i.e. risk-taking propensity, impulsivity). If the GABRA2 association were with such an intermediate or associated phenotype, this might affect power to detect an association if a CD-based phenotype were used, as we do here. Thus there are several reasons that might explain why our results differ from Dick et al., 2006.
