RESUMO
BACKGROUND: We evaluated the role that selected variants in serotonin transporter (5-HTT), dopamine receptor 2 (DRD2) and brain-derived neurotrophic factor (BDNF) genes play in PTSD symptom severity in an at-risk population. We also investigated the interaction between the genetic variants to determine whether these variables and the interactions between the variables influenced the severity of PTSD symptoms. METHODS: PTSD symptoms were quantitatively assessed using the Davidson Trauma Scale (DTS) in 150 participants from an at-risk South African population. All participants were genotyped for the 5-HTTLPR, DRD2 Taq1A and BDNF Val66Met polymorphisms. Gene-gene interactions were investigated using various linear models. All analyses were adjusted for age, gender, major depressive disorder diagnosis, level of resilience, level of social support and alcohol dependence. RESULTS: A significant interaction effect between DRD2 Taq1A and BDNF Val66Met variants on DTS score was observed. On the background of the BDNF Val66Val genotype, DTS score increased significantly with the addition of a DRD2 Taq1A A1 allele. However, on the BDNF Met66 allele background, the addition of an A1 allele was found to reduce total DTS score. CONCLUSIONS: This study provides preliminary evidence for an epistatic interaction between BDNF Val66Met and DRD2 Taq1A polymorphisms on the severity of PTSD symptoms, where both too little and too much dopamine can result in increased PTSD symptom severity.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Epistasia Genética , Receptores de Dopamina D2/genética , Transtornos de Estresse Pós-Traumáticos/genética , Adulto , Alelos , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Resiliência Psicológica , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Índice de Gravidade de Doença , Apoio Social , Transtornos de Estresse Pós-Traumáticos/psicologia , Inquéritos e QuestionáriosRESUMO
In this article, we attempt to uncover whether mass murders (the killing of multiple victims in single events) are preventable acts, the extent to which they are contributed to by biological and psychological factors, the notion that they are inextricably linked to mental illness, the role of the media, and what lessons can be learned by mental health professionals.
