Attention deficit-hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in children, which is associated with a high level of comorbidity among siblings of individuals with ADHD. Given the strongly hereditary nature of ADHD, it may include a group of neurobehavioral defects that can be seen with a higher prevalence in the patients’ siblings due to shared genetic origins. The present study was aimed at examining the prevalence rate and mean scores of neurological soft signs in children with ADHD and their siblings and comparing them with a healthy population. Thirty-two children and adolescents with ADHD and an age range of 7 to 16 years old and 32 siblings of them with the same age range were studied using attention deficit-hyperactivity checklist of DSM-IV-TR and K-SADS Questionnaire, and their neurological soft signs were evaluated using NES questionnaire. Afterwards, the results were compared with those of 32 healthy children and adolescents. The total scores on the test of assessing neurological soft signs were 8.34±4.9, 4.6±3.34, and 3±3.25 in the group with ADHD, the siblings, and the control group, respectively. There was a significant difference between the two groups and the control group (p<0.001). Examining neurological soft signs separately showed that the siblings obtained higher scores than the control group on the tests of fist-edge-palm, right-left separation, and audio-visual separation and coordination. In the present study, prevalence of neurological soft signs was higher among the siblings of the children with ADHD than the control group. These auxiliary signs may help find etiological signs of the disorder and identify individuals at risk.

Attention Deficit-Hyperactivity Disorder, Neurological Soft Signs, Neurological Evaluation Scale