Personality and mental health as mediators linking childhood maltreatment to intimate partner violence victimization: a Mendelian randomization–direction of causation twin study

Background: Childhood maltreatment elevates risk of later intimate partner violence (IPV) victimization, both major psychiatric risk factors. Personality and mental health have been proposed as mediators, but these pathways may be confounded by genetic and environmental influences shared across maltreatment, IPV victimization, and intermediary phenotypes. Here, we examined how maltreatment confers additional IPV risk beyond shared etiological liabilities. Methods: = 8406), we used Mendelian Randomization-Direction of Causation (MR-DoC) to examine causal mediation beyond genetic and environmental confounding. Lived-experience input informed design and interpretation. Findings: = 0.01-0.05). Interpretation: Maltreatment elevates risk of IPV victimization through its impacts on personality and mental health development, beyond risk conferred by shared genetic and environmental liabilities. Preventing IPV victimization among young people exposed to maltreatment requires greater understanding of how these psychological impacts operate within social transactional contexts, and developing targeted strategies that address them. Funding: British Academy/Leverhulme Trust.