IL2 and attention deficit-hyperactivity disorder: In 2010, Oades et al. reported the serum measurements of IL-1β, IL-2, IL-6, TNF-α, interferon-gamma (IFN-γ), IL-10, IL-13, and IL-16 in 21 children with ADHD who were treatment-naïve (mean age: 8.9 ± 1.4 years) (10).