School characteristics and children's mental health: A linked survey-administrative data study.

Mental health difficulties are childhood-onset with lifelong health, social and economic consequences. Children spend a large amount of time in schools, making schools an important context for mental health prevention and support. We examine how school composition and school climate, controlling for individual child-level characteristics, are associated with children's mental health difficulties (emotional and behavioural difficulties). Data from 23,215 children from 648 primary schools in England were analysed to examine the associations of school composition (size, gender, socioeconomic and ethnicity) and school climate with mental health (emotional symptoms, behavioural symptoms and above clinical cut-off scores) adjusting for individual child socio-demographic characteristics. We find that between 3% and 4.5% of the variation in children's mental health outcomes could be attributed to schools. Of this, small proportions were explained by school composition (1.4 to 3.8%) and larger proportions were explained by school climate (29.5 to 48.8%). Lower school socio-economic status was associated with higher behavioural symptoms (coef = 0.02 [95%CI: 0.01-0.04]) and slightly raised odds of high mental health difficulties (OR = 1.05, 95% CI: 1.01,1.09). More positive school climate was associated with lower emotional (coef = -0.09 [95%CI:-0.11,-0.08]) and behavioural (coef = -0.13 [95% CI,-0.15:-0.11]) symptoms and lower odds of mental health difficulties (OR = 0.78, 95%CI:0.74,0.81). Some associations between school factors and mental health were moderated by child sex and SES. School composition factors were weakly associated with children's mental health, whereas school climate explained a larger amount of between-school variation and appears a good target for universal prevention of mental health difficulties in children.