Catechol-O-methyltransferase Val158Met polymorphism in relation to aggressive schizophrenia in a Korean population

We examined the association between the Catechol-O-methyltransferase (COMT) Val158Met polymorphism and aggressive schizophrenia. The sample included 61 aggressive schizophrenic patients as well as 104 non-aggressive patients from psychiatric hospitals and 415 healthy volunteers in South Korea. In the case–control comparisons, there was no significant association between the aggressive schizophrenic patients and the COMT Val158Met polymorphism. Looking only at the subgroup of aggressive schizophrenic patients, however, we found a dose-dependent relationship between the Met allele and verbal aggression. In this subgroup, the Met carriers showed a higher verbal aggression score than those with the Val/Val homozygote. These findings support the hypothesized moderating role of the COMT gene in the aggressive behaviour in some schizophrenic patients, though they do not support the existence of a direct association between the COMT Val158Met polymorphism and aggressive schizophrenia case status in the Korean population.