Temporal Stability of ADHD in the High-IQ Population: Results From the MGH Longitudinal Family Studies of ADHD

ObjectiveThe diagnosis of attention-deficit/hyperactivity disorder (ADHD) in high-IQ youths remains controversial.MethodTo further explore the diagnostic validity of ADHD in this population, we studied two cohorts of high-IQ youths, both with and without ADHD, across a 4.5-year period.ResultsCompared to those without ADHD, high-IQ youths with ADHD had significantly higher rates of mood, anxiety, and disruptive behavior disorders at follow-up. In addition, ADHD status was a significant predictor for higher impairments across most social, academic, and family functional domains. Associations between baseline and follow-up IQ scores did not differ between groups. Syndromal persistence rates of ADHD were similar between high-IQ and average-IQ youths with ADHD.ConclusionsThese results provide further support for the predictive validity of ADHD in high-IQ youths. J. Am. Acad. Child Adolesc. Psychiatry, 2008; 47(7): 817–825.