S100B and attention deficit-hyperactivity disorder: Overall, considering total symptom ratings in the ADHD group the best predictors were increasing levels of IL-13 and IL-16 along with decreasing levels of S100B (R2 0.57, F(4,16) = 5.21, p = 0.007: β +0.59, +0.51, -0.54, p = 0.024, 0.019, 0.013, respectively) with a minor contribution from TNF-α.