Association between the Serotonin Transporter Gene (5-HTTLPR) and Anger-Related Traits in Korean Schizophrenic Patients

Abstract

Background: The serotonin transporter-linked polymorphic region (5-HTTLPR) short allele confers a general sensitivity to environmental stimuli, and anger is suspected to have a direct influence on aggressive behavior in schizophrenia. In the present study, we investigated whether the 5-HTTLPR gene was associated with aggression and/or anger-related traits in schizophrenia. Methods: A total of 103 schizophrenic patients, including 46 aggressive and 57 nonaggressive patients, were recruited from psychiatric hospitals in Korea. All of the aggressive patients had committed at least 2 significant violent acts requiring repeated confinement in each of the 2 weeks preceding study inclusion, as well as 2 or more serious assaults on others. Blood samples were collected from all patients for 5-HTTLPR genotyping, and all patients underwent clinical assessments for symptoms of schizophrenia, aggressive behavior and anger-related traits. Results: There was no significant difference in the distribution of the 5-HTTLPR genotype/alleles between the aggressive and nonaggressive patients. Aggressive patients carrying the s allele exhibited more anger-related traits than those with the l/l homozygotes, but this difference was not significant after correction for multiple testing. Furthermore, there was a dose-dependent relationship between the s allele and high angry temperament subscale scores in the aggressive patients. Conclusion: These findings seem to support the idea that 5-HTTLPR predisposes aggressive patients to exhibit more anger-related traits, though they do not support the existence of a direct association between 5-HTTLPR and aggressive behavior in schizophrenia in the Korean population; however, larger studies are needed.