Lower ADHD in high-IQ children
In children, high IQ appears to improve attention and is associated with lower levels of attention deficit/hyperactivity disorder (ADHD) problems, a recent study has shown.
ADHD and comorbid problems in 2,221 children (mean age 11.1±0.56 years; 50.8 percent female; mean IQ, 97.2±15.0) were assessed using questionnaires administered to the participants, to their parents and to their teachers.
There was a strong and positive linear correlation between all symptom domains of IQ scores and hyperactivity-impulsivity problems. Thus, higher IQ scores were associated with lower levels of attention and hyperactivity-impulsivity problems, according to both teacher and parent ratings.
Externalizing problems were also significantly and linearly correlated with IQ scores, although to a lesser degree. Intelligence and self-reported symptoms showed no significant associations.
In separate logistic regression analyses, parents and teachers identified attention problems as the major contributing factor to impaired performance at school. That is, attention problems negatively predicted extra telephone calls because of problems at schools, progress and performance below own capacity.
In a posthoc analysis, the predictive value of teacher-rated attention problems for child performance below own capacity was significantly stronger in the average to high IQ groups (p<0.001 for IQ scores 70–84, 85–99, 100–114 and 115–129).
This relationship was significant but attenuated for those with IQ scores 55–69 (p=0.02).
“[R]esults indicate that high IQ scores are related to decreased levels of ADHD problems, predominantly in relation to attention problems,” said researchers.
“[A]ttention problems were of all symptom domains the strongest predictor of repeating grades and suspected performance below own capacity,” they added.