The Impact of School Exclusion in Childhood on Health Outcomes in Adulthood: Estimating Causal Effects using Inverse Probability of Treatment Weighting

Previous evidence has suggested a strong association between school exclusion and mental health. However, as mental health risks are themselves related to the risk of experiencing a school exclusion, it has been challenging to determine the extent to which school exclusion impacts later mental health, as opposed to reflecting a marker for pre-existing risks. In this study we therefore used an inverse propensity weighting approach in the Next Steps dataset (N=6,534, from wave 1, 2014, to wave 8, 2015). We found that after weighting for propensity of treatment scores estimated based on a wide range of factors, there was a significant effect of school exclusion on a wide range of mental health and wellbeing outcomes. These results provide some of the most robust evidence to date that school exclusion harms long-term mental health. They imply that policies should aim to reduce exclusion and ensure access to preventative mental health support for those who experience a school exclusion.