Association of the Dopamine D4 Receptor Gene 7-Repeat Allele With Neuropsychological Test Performance of Children With ADHD

OBJECTIVE: Association between attention deficit hyperactivity disorder (ADHD) and the 7-repeat allele of a variant (a 48bp variable number of tandem repeats) in the dopamine D4 receptor gene (DRD4) has been widely documented. A meta-analysis of 21 studies revealed evidence of significant association. In this article the authors examine whether the DRD4 7-repeat allele is associated with performance on a variety of neuropsychological tasks in children with ADHD. METHOD: The presence or absence of the 7-repeat allele was determined in 133 drug-naive children 6 to 13 years of age who fulfilled diagnostic criteria for ADHD. These children were then assessed on several neuropsychological tests known to be associated with attention, impulse control, and response inhibition (the Continuous Performance Test, Matching Familiar Figures Test, Go/No Go Task, and Stop Task). Activity levels were assessed with an actigraph. Children with and without at least one 7-repeat allele were compared with each other and with c...