Childhood post-adoption experiences and the long-term trajectories of deprivation-specific neurodevelopmental problems: a longitudinal study of the English and Romanian adoptee cohort

Early institutional deprivation is associated with a co-occurring constellation of deprivation-specific problems (DSPs), including autism, ADHD, disinhibited social engagement (DSE), and cognitive impairment. While these difficulties often persist into young adulthood, substantial heterogeneity in developmental trajectories suggests that post-adoption environmental factors may influence recovery. This study adopts a transdiagnostic approach to examine how childhood experiences are associated with the long-term trajectories of these diverse neurodevelopmental and mental health domains. Using longitudinal data from 165 Romanian adoptees (total N = 217), we examined whether trajectories from ages 11 to young-adulthood for autism, ADHD, DSE, cognitive impairment, and mental health were predicted by childhood negative family/peer experiences and professional intervention (clinical psychological therapies and special educational support). We tested whether predictions differed between high versus low autism and ADHD symptom groups at age 11. Higher Professional Intervention levels were significantly associated with improving trajectories for autism, ADHD, DSE, and IQ, but not mental health outcomes. Multivariate analysis suggested complementary roles of clinical psychological therapies and special educational support; the former being more strongly associated with ADHD and DSE, and the latter with autism and IQ. Associations were observed across the symptom severity continuum for autism and ADHD, with comparable effect sizes found in both high and low symptom groups. Negative family and peer experiences showed some bivariate associations but were not significant predictors in multivariate models. Childhood professional intervention was associated with improved deprivation-specific outcomes, with effects across symptom severity levels, highlighting tractability despite strong persistence. The differential and complementary effects suggest comprehensive support requires both educational and clinical interventions.