Right hemisphere brain morphology, attention-deficit hyperactivity disorder (ADHD) subtype, and social comprehension

Social comprehension involves empathy for others' experiences and appropriate responses to nonverbal cues. Previous research using magnetic resonance imaging (MRI) has suggested a relationship between brain morphology and psychiatric syndromes, such as attention-deficit hyperactivity disorder (ADHD), that typically entail social difficulties. The right hemisphere, specifically, has been associated with social skill deficits, and numerous studies have also associated ADHD with social skill deficits. No studies, however, have examined the association of ADHD subtype with both social comprehension and right-hemisphere morphology. Fifty-nine children (6-12 years old) underwent MRI, from which the right hemisphere was classified into four morphologic subtypes. Children were also grouped by ADHD subtype or clinical control status. From Behavior Assessment System for Children (BASC) items, a social comprehension subscale was constructed. Analyses revealed significant differences in social comprehension based on ADHD subtype. Differences in social comprehension based on ADHD status were especially pronounced in children with atypical right-hemisphere morphology. Thus, the diagnosis of ADHD might be associated with underlying risk in the area of social comprehension, especially for children with atypical right-hemisphere morphology.