Behavioral and neuropsychological correlates of hyperactivity and inattention in Brazilian school children

Attempts at subtyping attention-deficit-hyperactivity disorder (ADHD) along the hyperactivity dimension are considered controversial. This study addresses this issue by dividing a non-clinical sample of Brazilian children (mean age, 9.4 years; SD, 2.9), who were attending a mainstream school in the Greater Rio de Janeiro area, into four behavioral domain groups (normal [NO, N=324], hyperactive/impulsive [HI, N=17], inattentive [IA, N=48], and combined [C, N=13]) on the basis of teacher ratings on an ADHD scale. The groups did not differ in intellectual level as determined by the Human Figure Drawing test. Comparisons were made between groups along the factorial dimensions extracted from the Composite Teacher Rating Scale, academic performance and neuropsychological measures were then performed. Our data showed that IA and C children are less independent and more prone to socialization problems than NO children, and that HI and C children are less anxious and fearful than IA children. Furthermore, the groups differed in academic and neuropsychological performance. The results could be considered consistent with the hypothesis that ADD with hyperactivity (ADD/+) and ADD without hyperactivity (ADD/-) represent singular nosological entities.