No evidence of association between Catechol-O-Methyltransferase (COMT) Val158Met genotype and performance on neuropsychological tasks in children with ADHD: a case-control study.

Background: Several studies have suggested an association between the functional Val158Met polymorphism in the Catechol-O-Methyltransferase (COMT) gene and neurocognitive performance. Two studies showed that subjects with the low activity Met allele performed better on the Wisconsin Card Sorting Test (WCST) and another study found an effect on processing speed and attention.

Methods: We set out to examine the association between the Val158Met polymorphism and performance on neurocognitive tasks including those tapping working memory, attention and speed, impulsiveness and response inhibition in a sample of 124 children with ADHD. Task performance for each genotypic group was compared using analysis of variance.

Results: There was no evidence of association with performance on any of the neurocognitive tasks.

Conclusions: We conclude that Val158Met COMT genotype is not associated with neurocognitive performance in our sample.