The relationship between speech difficulties and brain laterality in Attention Deficit Hyperactivity Disorder and Specific Learning Disorder

Abstract

Aim: We aimed to examine the behavioral determinants of brain laterality and their associations with speech difficulties in children with Attention Deficit Hyperactivity Disorder (ADHD) and Specific Learning Disorder (SLD).Methods: This cross-sectional study was conducted with a clinical sample of 7-18 years old patients with ADHD and/or SLD diagnosis. Patients’ sociodemographical, developmental and medical information were taken during their clinical interviews. Behavioral determinants of brain laterality were assessed by several motor tasks. These tasks were “handwriting” for handedness, “looking through the telescope” for eyedness, and “hitting the ball or standing on one foot” for footedness.Results: A total of 130 patients participated in the study. Left side preference and crossed laterality were common in patients with SLD (with or without comorbid ADHD) but not in patients with pure ADHD. Left eyedness/footedness were associated with speech disorders (p<0,05).Conclusion: This study has shown that even after controlling for other factors affecting the development of brain laterality SLD, but not ADHD, is associated with left-sided preference and cross laterality. The relationship between speech disorders and left-eyedness/footedness in ADHD and SLD patients suggests that development of brain laterality is actually mediated by speech development.