Child maltreatment and mental health in later life: The moderating role of longitudinal lifestyle patterns in a UK cohort.

Background: A healthy lifestyle may buffer the adverse mental health effects of childhood adversity. However, most studies assess isolated lifestyle behaviors at a single time point, failing to capture their synergistic and dynamic nature over the life course. The interplay between child maltreatment (CM) and long-term lifestyle trajectories in shaping mental health outcomes remains underexplored.

Objective: To examine how lifestyle trajectories moderate the association between CM and later-life mental health, and whether these moderation effects differ by sex and age.

Participants and setting: This study included 39,437 adults aged 40-71 years (53.03 % female; 97.69 % White) from the UK Biobank.

Methods: Group-based trajectory modeling identified patterns of combined lifestyle behaviors over time. Poisson regression and general linear regression were used to assess the associations between CM, lifestyle trajectories, and mental health outcomes.

Results: CM was associated with poor mental health in a dose-response manner (p < 0.001), with emotional abuse and neglect showing stronger effects. Five lifestyle trajectories were identified: "persistent unhealthy", "increasing healthy", "moderate healthy", "decreasing healthy", and "persistent healthy." These lifestyle trajectories significantly moderated the association between CM and depression, anxiety, and reduced mental well-being, but not for self-harm. Moderation effects were more pronounced among younger adults.

Conclusions: The study underscores the value of life course frameworks in addressing the long-term psychological impacts of CM. By linking early developmental risk with modifiable health behaviors across the lifespan, our findings inform strategies aimed at advancing population-level mental health equity and resilience.