Early-life family relationships, children’s mental health trajectories, and their prospective associations with adolescent distrust and social isolation

Early-life family relationships have been linked to childhood emotional (internalising) and behavioural (externalising) problems and adolescent social functioning but developmental pathways between them remain underexplored. We examined whether trajectories of children’s internalising and externalising problems mediate between low-quality early family relationships and adolescent social outcomes, including interpersonal distrust and low perceived social support (perceived social isolation). Using a UK-representative cohort ( N = 11 , 069 ), we modelled internalising and externalising problem trajectories (ages 3–11) via latent growth curves and tested whether their growth parameters mediated associations between mother–child and interparental relationships (age 3) and social outcomes (age 14), adjusting for child, family, and neighbourhood characteristics. Higher interparental relationship quality predicted lower distrust and social isolation, both directly and indirectly via lower baseline externalising problems, whereas indirect pathways through internalising parameters were non-significant. Findings for the mother–child relationship were more nuanced, however, with higher relationship quality predicting greater distrust and social isolation, while paths via slopes (positive) and quadratic components (negative) acted in opposing directions for both internalising and externalising problems, yielding no net mediation for distrust and a small protective effect for social isolation. Interventions reducing parental discord in early childhood alongside addressing children’s emotional and behavioural difficulties may help reduce adolescent social disconnection.