2014) and is mediated by global differences in white matter structural network topology (Panigrahy et al. 2015). These findings suggest that alteration of large‐scale network organization can adversely affect cognitive dysfunction in children with surgically treated CHD. We now report that scores on CADS ADHD tests are also mediated by white matter global and regional topologic differences. Additionally, our exploratory analysis found that APOE genotype exerted an effect on structural topology and CADS scores in these adolescents. The gene discussed is APOE; the disease is attention deficit-hyperactivity disorder.