High intelligence and the risk of ADHD and other psychopathology.

Abstract

<b>Background</b>High intelligence may be associated with positive (adaptive, desired) outcomes, but may also come with disadvantages.<b>Aims</b>To contribute empirically to the debate concerning whether a trade-off in IQ scores exists in relation to attention-deficit hyperactivity disorder (ADHD) and related problems, suggesting that high intelligence - like low intelligence - increases the risk of ADHD.<b>Method</b>Curves of the relation between IQ score and ADHD problems were fitted to questionnaire data (parent, teacher, self-report} in a population-based study of 2221 children and adolescents aged 10-12 years. Externalising and internalising problems were included for comparison purposes.<b>Results</b>Higher IQ score was most strongly related to fewer attention problems, with more rater discrepancy in the high <i>v.</i> average IQ range. Attention problems - but only minimally hyperactivity/impulsivity problems - predicted functional impairment at school, also in the higher IQ range.<b>Conclusions</b>Attention problems in highly intelligent children are exceptional and affect school performance; they are therefore a reason for clinical concern.