Variation in catechol-O-methyltransferase val158 met genotype associated with schizotypy but not cognition:: A population study in 543 young men

Background: Increased catechol-O-methyltransferase activity associated with variation in catechol-O-methyltransferase valine(158) methionine genotypes may result in reduced dopamine neurotransmission in the prefrontal cortex and thus contribute to the poor performance of frontally mediated cognitive tasks and The occurrence of associated negative symptoms observed in patients with schizophrenia; however reported associations between catechol-O -methyltransferase valine(158) methionine genotypes and measures of cognition have not been consistent. Methods: Catechol-O-methyltranferase genotyping, measures of schizotypy, cognitive measures of memory and attention, as well as the antisaccade eye movement task, a measure sensitive to prefrontal cortical function, were obtained in a sample of 543,young men representative for that age group (mean age 21 years). Results: None of the cognitive measures was associated with catechol-O-methyltransferase valine(158) methionine genotypes; however, there was an effect of high-activity allele loading on schizotypy, in particular the negative and disorganization dimensions. Conclusions: Previously reported inconsistencies in the relationship between catechol-O-methyltransferase valine(158) methionine genotypes and cognition were not resolved; however catechol-O-methyltransferase genotype may affect expression of negative schizotypy by direct or indirect effects on central dopamine neurotransmitter signaling.