Abstract / Summary
Objective: We compared serum neuregulin-1 (NRG-1), neuregulin-2 (NRG-2), and neuregulin-3 (NRG-3) levels between children and adolescents with attention-deficit/hyperactivity disorder (ADHD) and healthy controls and investigated their relationship with ADHD symptom severity.Methods: This study included 101 drug-naive patients with ADHD (aged 8-18 years) and 51 age-and sex-comparable healthy controls.Diagnoses were confirmed using the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime Version.Symptom severity and comorbid symptoms were assessed using the Turgay DSM-IV-Based Scale and the Revised Child Anxiety and Depression Scale.Serum NRG-1, NRG-2, and NRG-3 levels were measured using enzyme-linked immunosorbent assay.Results: The groups did not differ in age, sex, or body mass index (BMI) (p ＞ 0.05).Serum NRG-1 and NRG-3 levels were significantly higher in the ADHD group than in controls (p ＜ 0.001 and p = 0.003, respectively), whereas NRG-2 levels did not differ (p = 0.205).Logistic regression analyses demonstrated that elevated NRG-1 and NRG-3 levels were independently associated with ADHD group status after controlling for age, sex, and BMI.In exploratory correlation analyses within the ADHD group, NRG-1 levels showed a modest positive correlation with hyperactivity/impulsivity scores (rS = 0.212, p = 0.033), whereas NRG-3 levels were negatively correlated with BMI (p = 0.013).Serum NRG-2 and NRG-3 levels were positively correlated (p ＜ 0.001).Conclusion: Elevated serum NRG-1 and NRG-3 levels in children and adolescents with ADHD suggest that neuregulin family members may represent peripheral biological correlates of neurodevelopmental processes associated with ADHD.These findings support further investigation of NRG-1 and NRG-3 as potential peripheral biomarkers in ADHD.