Perceived emotional support mediates the association between childhood family adversity and adolescent mental health in the UK millennium cohort.

Childhood family adversity is associated with increased risk of developing mental health problems over the life course. We investigated how perceived emotional support in adolescence may mitigate the impact of childhood family adversity on adolescent mental health. We used longitudinal data from the UK Millennium Cohort Study on 9,269 children followed to age 17 years. Individuals were assigned to exposure trajectories characterised using group-based trajectory models that included measures of poverty and family dynamics up to age 14 years. Using counterfactual causal mediation analysis and four-way decomposition modelling approach, we evaluated how perceived emotional support at age 14 (measured using the three-item Short Social Provisions Scale) influences the association of childhood family adversity trajectories on mental health at ages 14 and 17, assessing the relative contributions of mediation and interaction simultaneously. Compared with children experiencing low family adversity and poverty, those exposed to childhood family adversity were almost three times more likely to experience poor mental health (RR 2·99, 95% CI 2 ·41 to 3·57) at age 14 and age 17 (RR 2·58, 95% CI 2·09 to 3·06). Perceived emotional support mitigates up to 18% (95% CI: 9% to 26%) of this effect at age 14, and 13% (95% CI: 5% to 22%) at age 17, mainly due to interactive mechanisms. Childhood family adversity has a strong effect on mental health, which is partially mitigated by emotional support in adolescence. Policies that support positive family functioning may be particularly beneficial for children who have experienced adversity.