Injuries/Violence
Child maltreatment, adult partner violence, and age at dementia diagnosis: A sequential causal mediation analysis in the UK Biobank Marie-Céline Schulte* Marie-Céline Schulte Schulte Schulte London School of Hygiene and Tropical Medicine
Background: Child maltreatment (CM) and adult partner violence correlate with late-onset dementia and a range of established risk factors. However, their associations with age at diagnosis and young-onset dementia (YOD) remain poorly characterized.
Methods: Among 147,938 UK Biobank participants, we identified Alzheimer’s-related, vascular, and frontotemporal dementia cases. We examined associations between CM, adult partner violence, age at dementia diagnosis, and dementia diagnosed at age £68 years accounting for diagnostic delays. Weibull accelerated failure time models estimated time from age 18 to diagnosis. Single-mediator and sequential causal mediation models estimated direct effects of CM on dementia diagnosed at or before age 68 years,, indirect effects operating through adult partner violence and 22 established risk factors, as well as proportions mediated, under model assumptions. We calculated E-values for bias quantification.
Results: Of 915 cases, 128 were diagnosed £68 years of age. Individuals CM and partner violence exposed had a dementia diagnosis more than two years younger on average additively than unexposed participants, assuming independent effects. Adult partner violence, socioeconomic deprivation, excessive alcohol consumption, and obesity (body mass index ³30kg/m2) together mediated an estimated 78% of the association between CM and YOD (Adjusted OR: 1.51; 95% CI: 1.01, 2.29), conditional on model assumptions. E-values for indirect effect odds ratios ranged from 1.71 to 2.10, suggesting increasing robustness against unmeasured confounding across the four mediation models.
Discussion: Adult partner violence and midlife risk factors may play a role in associations between CM and younger dementia diagnosis, though interpretations depend on model assumptions.