Causal Effects of School Closures on Childhood and Adolescent Mental Health During the COVID-19 Pandemic in Ontario, Canada

COVID-19 mitigation policies led to widespread education disruption, impacting an estimated 5.7 million school-aged children and youth in Canada. Social interactions, intellectual stimulation, and the surrounding environment during school hours play a key role in the development of school-aged children and youth. The effects of early education disruption on mental health can be long lasting. It is now widely understood that the pandemic precipitated an unprecedented mental health crisis among children and youth both in Canada and around the world. However, there is little to no evidence on the impact that pandemic containment measures have had on childhood and youth mental health. Our study aims to evaluate changes in the mental health of children and youth in Canada pre- and post-pandemic, the potential causal role that school closures played, and identifying who were most affected. To that end, we analyze multiple waves of the Canadian Health Survey on Children and Youth, as well as Ontario electronic health records data linked with administrative population data on demographic and socioeconomic variables, to: i) characterize national and province/territory-specific changes in mental health outcomes among school-aged children and youth from before the pandemic to during/after the pandemic, ii) estimate the role that school closures played on the decline of the mental health of school-aged children and youth in Ontario, and iii) identify significant unexplained disparities in adverse mental health outcomes between adjacent census tracts within Ontario. Our study will help inform evidence-based policies on education responses to future pandemics that consider the broader social and emotional needs of children and youth, as well as policy recommendations for community-based health promotion and intervention programs that increase awareness of mental health issues in children and youth and guiding the equitable allocation of services to communities of greatest need.