Personality traits and cortical structure link childhood maltreatment to impulsivity

Background: Childhood maltreatment is associated with behavioural dysregulation, including heightened impulsivity, but the psychological and neurobiological pathways linking early adversity to impaired self-regulation remain unclear.Methods: This study tested theory-informed statistical mediation models to examine whether specific childhood maltreatment subtypes were associated with impulsivity through region-specific cortical thickness and personality traits. Sixty-one healthy adults completed the Childhood Trauma Questionnaire, NEO Five-Factor Inventory, and Barratt Impulsiveness Scale, and 59 also underwent 3 T structural MRI. An exploratory extension was conducted in an affective disorder cohort.Results: In healthy adults, associations between maltreatment and attentional, motor, and non-planning impulsivity were primarily indirect through personality traits. Physical neglect was associated with lower agreeableness and conscientiousness, whereas emotional neglect was associated with higher neuroticism and lower conscientiousness and extraversion. Cortical thickness further contributed to these pathways, particularly in the anterior cingulate cortex and ventral medial-orbitofrontal regions. In the affective disorder cohort, the maltreatment-personality-impulsivity structure was partly retained, but cortical involvement differed, with pathways involving ventral cingulate, lateral prefrontal, and medial orbitofrontal regions. These clinical findings should be interpreted as exploratory.Conclusions: Findings support a multilevel framework in which childhood maltreatment is statistically associated with impulsivity through personality traits, with additional contribution from cortical thickness in regulatory brain systems. Clinical context may be associated with differences in neurobehavioral organisation linking early adversity, personality, and impulsivity.