Atypical frontal brain activation in ADHD: preschool and elementary school boys and girls.

OBJECTIVE

To investigate patterns of frontal brain activation in unmedicated preschool and school boys and girls with attention-deficit/hyperactivity disorder (ADHD).

METHOD: Baseline electroencephalographic activity of 117 children (66 aged 4 years, 51 aged 8 years) was subjected to power spectral analysis, and laterality scores were determined.

RESULTS

Boys with ADHD exhibited a less right-lateralized frontal activation pattern than normal control boys. Girls with ADHD displayed a more right-lateralized frontal activation pattern than normal control girls. This finding applied to children at both 4 1/2 and 8 years of age. There was no difference between children with ADHD and children with ADHD plus oppositional defiant disorder.

CONCLUSIONS

This pattern of frontal brain activation is in line with magnetic resonance imaging studies of ADHD. It could be demonstrated in children as young as 4 1/2 years, as well as in school-age children. The opposite direction of asymmetry in boys and girls stresses the importance of gender-specific analyses in ADHD.