Longitudinal associations between school environment and mental health from childhood through early adulthood

Children spend a significant part of their lives at school. However, the long-term effects of the school environment on mental health are still not well understood, especially using genetically sensitive designs. Here, we examine the associations between perceived school environment and mental health from childhood to emerging adulthood, and the genetic and environmental factors that underlie these relationships. Using data from over 6,500 participants aged 7–21 from the Twins Early Development Study (TEDS), we found consistent, moderate associations between perceived school environment and mental health (average r ≈ .19). School environment cumulatively explained mental health problems, explaining 26–56% of the variance both contemporaneously and over time. These associations remained substantial after adjusting for genetic predisposition using psychiatric polygenic scores, family socioeconomic status and earlier mental health problems, although the effect sizes were smaller (6–30% of variance explained). Twin analyses showed that not only was psychopathology highly heritable (~ 61%), but also how children experience school was partly due to genetics (~ 46%). The association between perceived school environment and mental health was largely accounted for by shared genetic influences (~ 70%), supporting the role of gene–environment correlation in mental health outcomes. We show that perceived school environments are significantly associated with mental health across development, even after accounting for genetic predisposition, SES and earlier mental health problems. Using a genetically sensitive, longitudinal approach, this research provides a conservative yet clearer estimate of how school environments might influence mental health outcomes over time, because participants completed their schooling more than a decade ago, when reported youth mental health problems were lower, and school environments were likely less pressured. Our findings emphasise the importance of understanding the school environment as a potential setting for prevention and support and underscore the need for further research to identify modifiable factors that could improve children’s wellbeing.