S100B and attention deficit-hyperactivity disorder: In summary, we report on a pilot study of serum samples from medication-naïve children with and without ADHD, and a group taking psychostimulants for 1) S100B, 2) tryptophan metabolites, 3) 17 amino-acids, and 4) a set of pro- and antiinflammatory interleukins as potential indicators of the integrity of glial cell function (hypothesis 1: decreased in ADHD), of the presence of toxic over-protective features of amino-acid metabolism (hypothesis 2: in ADHD) and the immunological activity influencing metabolism (hypothesis 3: an imbalance).