Efficacy of Methylphenidate in ADHD Children across the Normal and the Gifted Intellectual Spectrum.

Objective: This study evaluates whether attention-deficit/hyperactivity disorder (ADHD) children with a borderline intelligence quotient (IQ) (70≤FSIQ<80), normal IQ (80≤FSIQ<120) and high IQ (FSIQ≥120) respond differently to psychostimulant treatment.

Method: 502 children, aged 6 to 12 years, with an IQ range from 70 to 150 participated in a two-week, double-blind, placebo-controlled, crossover methylphenidate (MPH) trial.

Results: In addition to differences in socioeconomic background and parental education, higher IQ children were found to present with less severe symptoms. No significant differences were found with regards to treatment response.

Conclusion: ADHD children within the normal and high levels of intellectual functioning all respond equally to psychostimulant treatment, and that proper medication management is necessary for all children with the disorder.