S100B and attention deficit-hyperactivity disorder: In this dual three-month-phase clinical trial on children and adolescents with ADHD, we aimed at (1) evaluating differences in serum S100B levels between ADHD patients and healthy controls; and (2) assessing gradual changes in both serum S100B concentrations and clinical symptoms (as per attention scores) after initiating treatment with a combination of MPH, aMT and ω-3 PUFAs.