No Elevated Genomic Damage Despite High Oxidative Stress and Homocysteine Levels Among ADHD Children

This study aimed to examine oxidative stress and DNA damage in medication-naïve children with attention deficit hyperactivity disorder (ADHD), focusing on total oxidant and antioxidant levels, homocysteine, vitamin B12 (VB12), folic acid (FA) and vitamin D (VD). Forty-two medication-naïve children diagnosed with ADHD and 36 age- and sex-matched healthy controls participated in the study. Biochemical analyses included measurements of total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), homocysteine, VB12, FA and VD levels via ELISA. Genomic DNA damage was evaluated through the comet assay. Children with ADHD exhibited significantly higher TOS, OSI and homocysteine levels, indicating increased oxidative stress (respectively t = 2.956, p = 0.005; t = 3.218, p = 0.002; t = 2.868, p = 0.006). However, contrary to expectations, DNA damage parameters (tail intensity, tail moment and tail migration) were significantly lower in the ADHD group than in controls (respectively t = -3.830, p = 0.000; t = -3.871, p = 0.000; t = -2.340, p = 0.022). VD levels were also higher in the ADHD group (t = 2.313, p = 0.023), while no significant group differences were observed in VB12 or FA (p > 0.05). Despite increased oxidative stress, children with ADHD showed no signs of elevated genomic damage. These findings suggest the presence of compensatory mechanisms such as efficient DNA repair or enhanced antioxidant responses in this population. The unexpected pattern of elevated VD and stable genomic integrity highlights the complexity of biological processes underlying ADHD and the importance of considering adaptive cellular factors in biomarker research.