SIRT-1 (r = − 0.430, p = 0.001), Nrf-2 (r = − 0.446, p < 0.001), and HO-1 (r = − 0.424, p = 0.001) levels were negatively correlated with ADHD symptom severity. The gene discussed is HMOX1; the disease is attention deficit-hyperactivity disorder.