Evaluation of the levels of arginine/nitric oxide and associated molecules and orexin and the factors that may be related to them in children aged 6-12 years diagnosed with attention deficit hyperactivity disorder

Although attention deficit hyperactivity disorder (ADHD) is a common neuropsychiatric disorder in childhood, its etiology has not been fully elucidated yet. In this study, it was aimed to investigate the levels of arginine/nitric oxide (NO) and associated molecules and orexin-A (OXA), which is thought to play a role in the etiology of ADHD and to compare the findings with healthy controls. Our sample was composed of 30 ADHD and 30 healthy control cases aged 6-12 years, admitted to the outpatient clinic of Fırat University Faculty of Medicine Department of Child and Adolescent Psychiatry. Sociodemographic data form, Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version-Turkish Version, DSM-IV-Based Child and Adolescent Behavioral Disorders Screening and Rating Scale, Conners'Parent/Teacher Rating Scale-Revised Long Form, Child Depression Inventory, State-Trait Anxiety Inventory for Children applied to all subjects. All cases included in the study were evaluated in terms of serum arginine, NO, asymmetric dimethylarginine (ADMA), adrenomedullin, insulin-like growth factor-1 (IGF-1), and OXA levels. Then, methylphenidate treatment was started for ADHD cases, and blood parameters were reevaluated in the tenth week of treatment. In the ADHD group than the control, it was found to be arginine, ADMA levels significantly higher; NO, adrenomedullin, and IGF-1 levels significantly lower. OXA levels did not differ significantly between groups. Post-treatment levels of arginine, ADMA, OXA were found significantly lower than pre-treatment. No significant difference in the pre-treatment and post-treatment NO, adrenomedullin, and IGF-1 levels were found. There was no correlation between scale scores and blood parameters. As a result, these differences in blood parameters that are detected in the ADHD group, appears to be a worthy area for researching. Studies that are going to be performed after more prolonged treatment with large sample groups will be able to present new information about the changing neurobiological process depending on the etiology and treatment of ADHD.