Parental care moderates the influence of MAOA-uVNTR genotype and childhood stressors on trait impulsivity and aggression in adult women

Abstract

Adverse childhood experiences are associated with poor mental health outcomes, including vulnerability to mood disorders and/or antisocial behavior. A functional polymorphism in the regulatory region of the monoamine oxidase A gene (monoamine oxidase A untranslated variable nucleotide tandem repeat, MAOA-uVNTR) may moderate the degree of risk conferred by early trauma. Experiential factors may mitigate or exacerbate the effects of trauma on individuals at genetic risk. We examined the association among MAOA-uVNTR genotype, early stress (family death, family separation, parents' divorce, physical and/or sexual abuse), quality of parental care, and disadvantageous outcomes (trait impulsivity/aggression and depression severity) in adult women. Diagnostic assessments were completed for 159 female participants. All were either healthy or were diagnosed with major depressive disorder or bipolar disorder. Participants were assessed for lifetime trait aggression and impulsiveness and current severity of depression, and were genotyped for the MAOA-uVNTR polymorphism. Participants rated the level of parental care they experienced, and were asked to report specific childhood stressors and abuse. High perceived parental care mitigated the effect of a childhood stressor on impulsivity scores in low-expressing MAOA-uVNTR allele carriers, but level of perceived care had no effect in the group homozygous for the high-expressing MAOA-uVNTR allele. Gene-environment interactions did not influence depression severity in the mood disorder group, indicating that the effects of parenting we observed in our participants were independent of depression status. These results suggest that gene-environment interactions influence not only disadvantageous outcomes, but also sensitivity to features of the environment that could alleviate these outcomes.