S100B and attention deficit-hyperactivity disorder: When comparing serum S100B levels at different time points in the ADHD group, a significant increase was observed at T3 in relation to T0 [S100B mean values: 0.2204 (0.089) μg/L at T0 vs. 0.3339 (0.1447) at T3 (p < 0.001)], as well as significantly higher S100B concentrations at T6 compared to T0 [S100B mean values: 0.2204 (0.089) μg/L at T0 vs. 0.3408 (0.1527) μg/L at T6 (p < 0.001)].