['Suicidal behavior is often correlated with other-directed aggression, which is partially mediated by catecholaminergic neurotransmission. Catechol-O-methyltransferase (COMT) is an enzyme involved in catecholamine inactivation. In this study, we examined the influence of a functional COMT (V158M) polymorphism on suicidal behavior and anger-related traits.', 'This polymorphism was examined in 149 German suicide attempters and 328 German control subjects. Both groups were administered self-report questionnaires for anger-related traits.', 'There was no overall difference in allele/genotype frequency between patients and control subjects; however, the low-activity L-allele and genotype frequencies were higher among violent suicide attempters. For anger-related traits, a multivariate effect of the COMT genotype was observed after controlling for age and educational level. LL-carriers expressed their anger more outwardly, whereas HH-carriers expressed it more inwardly and reported more state anger, as assessed by the self-report questionnaire.'] Is a functional single nucleotide polymorphism ( V158M ) in the COMT gene associated with aggressive personality traits?