The immune system’s role in attention deficit hyperactivity disorder development

Attention deficit hyperactivity disorder (ADHD) is one of the most common disorders in minors. Although its symptoms are well-described, the mechanisms regarding physiopathology are not yet fully known. Most studies in the literature are focused on the genetic and neurochemical aspects that differ in this population in comparison to healthy subjects. However, some data suggest that ADHD might be linked to alterations in the immune system as well, which have not been largely investigated so far. The aim of this cross-sectional study is to investigate baseline levels of inflammatory and oxidative stress markers and DNA damage in a cohort of children with ADHD and a healthy control group. Serum interleukin-1 beta (IL-1β), thiobarbituric acid reactive substances (TBARS) and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were measured. The results revealed significantly higher levels of IL-1β (t = 4.099; df = 80; p < 0.001), TBARS (t = 13.629; df = 85; p < 0.001) and 8-OHdG (t = 10.382; df = 85; p < 0.001) in ADHD patients than in healthy controls. This study suggests that the immune system is likely involved in the pathophysiological development of ADHD.