Monocyte/High density lipoprotein (HDL) ratio in children and adolescents with attention deficit hyperactivity disorder

Attention Deficit Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. Recent studies suggests that immune dysregulation and inflammation may play a role in its pathophysiology. The monocyte-to-high-density lipoprotein (HDL) ratio (MHR) has been proposed as a novel inflammatory marker. This study aimed to investigate the relationship between ADHD and MHR. Material and Methods: This retrospective, single-center study included 67 children and adolescents diagnosed with ADHD and 75 age- and sex-matched healthy controls. Hemogram and lipid panel parameters were retrieved from medical records, and MHR was calculated for each participant. Monocyte levels, HDL levels, and MHR values were compared between the ADHD and control groups. Results: Monocyte levels were significantly higher in the ADHD group compared to the controls (p = 0.028). However, no significant differences were found between the groups in terms of HDL levels (p = 0.783) or MHR (p = 0.076). Conclusions: The findings suggest that systemic inflammation may contribute to the pathophysiology of ADHD, as indicated by elevated monocyte levels. However, the lack of a significant difference in MHR suggests that lipid metabolism alterations may not play a primary role in ADHD-related inflammation. Further studies with larger samples and more inflammatory markers are needed to clarify the role of immune dysregulation in ADHD.