CRP levels were modestly higher (3.50 ± 1.59 vs. 2.86 ± 1.68, p = 0.036), and ferritin levels were lower in the ADHD group (49.78 ± 46.68 vs. 71.54 ± 63.80, p = 0.035). This evidence concerns the gene CRP and attention deficit-hyperactivity disorder.