The ADHD cohort comprised of 335 complete parent–child trios of European descent recruited from pediatric and behavioral clinics that passed genotype and CNV analysis quality metrics (see Methods). A set of 2026 ethnically matched, disease-free children was used as a healthy control group. All samples were genotyped using the Illumina HumanHap550K BeadChip and a single consistent protocol. Genotype data were uniformly analyzed for CNVs using Illumina's BeadStudio software in combination with a customized adaptation of the circular binary segmentation algorithm.29
