Possible Effect of COMTVal158Met Polymorphism on the Association between Childhood Maltreatment and Externalizing Behavior: A Preliminary Study

Aims: Over the course of the past decades, studies on child maltreatment have increasingly adopted multiple levels of analysis (particularly by the inclusion of genetics factors) on the basis of the variability in children’s responses to stressful life events. This is a preliminary study on the effects of child maltreatment in a sample of adolescents according to this perspective.

Study Design: Case-control study.

Methodology: We investigated the moderating effect of COMT Val158Met polymorphism onthe association of child maltreatment with a range of externalizing behavior - assessed by the Child Behavior Check List/6-18 scale - in a sample composed of 52 maltreated children and adolescents and 90 healthy controls aged 10-18. Maltreatment was recorded on the basis of the presence/absence of physical contact.

Results: COMT Val158Met polymorphism interacts with physical contact abuse to influence externalizing behavior (p=.04), with both genetic (p=.03) and environmental risk factor (p=.003) having a significant main effect. Similar results were found considering the rule-breaking component of externalizing behavior, and the main effect of maltreatment was highly significant in all analyses performed.

Conclusion: This preliminary study supports the hypothesis that the variability in children's responses to maltreatment might be partially explained by individual genetic differences. Considering the presence of physical contact as a risk factor we could explain inconsistence of findings in literature on GxE in maltreatment.