Both groups displayed significant increases in GFAP levels at 2 h-post heading (ADHD: 7.75 pg./mL [1.41, 14.10 pg./mL], p = 0.019; Non-ADHD: 7.91 pg./mL [1.71, 14.14 pg./mL], p = 0.015), and GFAP levels in both groups were normalized to baseline levels at 24 h-post heading (ADHD: −2.45 pg./mL [8.67, 3.76 pg./mL], p = 0.446; Non-ADHD: 4.00 pg./mL [−2.16, 10.15 pg./mL], p = 0.210; Figure 3B). Here, GFAP is linked to attention deficit-hyperactivity disorder.