Heart rate variability in children with attention deficit and hyperactivity disorder and its relation with clinical parameters

Aim: The aim of this study is to evaluate the heart rate variability (HRV)parameters of children with ADHD without treatment and to compare with the healthy peers and to investigate the relation of these parametres with clinical variables. Method: Fifthy-one children aged 8 to 12 years who are diagnosed as ADHD at Inonu University Medical School Child and Adolescence Psychiatri Department were enrolled to the study. The diagnosis of ADHD was based on DSM-IV criteria and Child and Adolescent Schedule of Affective Disorders and Schizophrenia (K-SADS). Also age and sex matched 51 healthy peers of these children made up the control group. All of the patients and controls were evaluated with State-Trait Anxiety Inventory (STAI)Children's Depression Inventory Scores (CDIS) and Childhood Anxiety Sensitivity Index (CASI). The parents were asked to fill the sociodemographical information form and the revised Conners? Parent Rating Scale (CPRS-R). Twenty-four hour cardiac rhythm Holter monitoring was performed and HRV parameters of patients and controls were compared. Results: There was no difference between children with ADHD and healthy controls in terms of HRV parameters. Also no significant difference was observed when subtypes of ADHD were compared among HRV parameters. STAI, CDIS and CASI scores of children with ADHD was significantly higher than that of controls. Discussion: Children with treatment free ADHD and healthy controls were compared among HRV parameters of 24-hour rhythm Holter monitoring which is a sensitive method for evaluation of autonomic nervous system (ANS) functioning and there was no significant difference between patients and controls. These results support that there is no different ANS functioning measured by HRV parameters in patients with ADHD. Further investigations are needed to evaluate ANS functions in patients with ADHD.