Adverse Childhood Experiences, Allostatic Load, and Adult Health: The Mediating and Moderating Role of Personality in a Nationally Representative US Study

Objective: Adverse childhood experiences (ACEs) are strong risk factors for biological dysregulation, morbidity, and mortality over the lifespan. Although research has begun investigating potential risk and resilience processes that mediate and moderate these associations, little research has examined the unique role that personality plays in linking ACEs with biological and clinical health in adulthood. Method: To investigate, we used cross-sectional data from the 2006 and 2008 assessments of the nationally representative US Health and Retirement Study ( n =9708). Exposures included any ACEs (before age 18) and specific ACEs (i.e., parental substance use, physical abuse, repeating a school year). Mediators were personality characteristics, measured using the top quartile (Yes/No) of Big Five personality characteristics (i.e., conscientiousness, agreeableness, neuroticism, openness, extraversion). Outcomes were allostatic load and the number of chronic diseases present in adulthood. We used causal mediation analysis to estimate the extent to which personality mediated and/or moderated the association of ACEs with each outcome. Results: Individuals with any ACEs had 5% higher allostatic load (Adjusted incidence rate ratio [aIR]: 1.05, 95% CI [1.01, 1.09]) and 9% more chronic diseases (aIR: 1.09, 95%CI [1.06, 1.12]) than those with no ACEs. There was a clear dose-response relationship, such that participants with the maximum of three ACEs had 20% higher allostatic load and 25% more chronic diseases in adulthood than those with no ACEs. Neuroticism mediated and moderated the association of any ACEs with chronic diseases, accounting for approximately 44% of this ACE-morbidity association. Conclusions: ACEs are associated with higher allostatic load and morbidity, with neuroticism both mediating and moderating the ACE-morbidity association. Research is needed to determine whether and, if so, when interventions targeting neuroticism may help mitigate the substantial burden of ACEs on lifespan health.