The following variables showed significantly increased odds of being classified as having ADHD: when a child was male (OR 2.55, 95% CI 2.22–2.92); obese (OR 1.45, 95% CI 1.19–1.77); had DEP (OR 11.94, 95% CI 9.75–14.61); had ANX (OR 9.35, 95% CI 7.82–11.18); belonged to ≤ 200% POVERTY level (OR 1.33, 95% CI 1.17–1.51); had INS (OR 1.54, 95% CI 1.16–2.04); had someone SMOKE (OR 1.98, 95% CI 1.75–2.25); used COMP for ≥1 hour for the purpose other than school work in a weekday (OR 1.52, 95% CI 1.31–1.77); or watched TV for ≥1 hour (OR 1.82, 95% CI 1.55–2.13); than the respective reference group. This evidence concerns the gene INS and attention deficit-hyperactivity disorder.