Assessing the impact of the COVID-19 pandemic on the mental health-related hospitalization rate of youth in Canada: an interrupted time series analysis.

Introduction: This study evaluated the effect of the COVID-19 pandemic on temporal trends in mental health and addiction-related inpatient hospitalization rates among youth (aged 10-17 years) in Canadian provinces and territories (excluding Quebec) from 1 April 2018 to 5 March 2022.

Methods: We conducted an interrupted time series analysis across three periods: T0 (pre-pandemic: 1 April 2018 to 15 March 2020); T1 (early pandemic: 15 March 2020 to 5 July 2020); and T2 (later pandemic: 6 July 2020 to 5 March 2022).

Results: Pre-pandemic mental health and addiction-related hospitalization rates had significant regional variability, with weekly rates from 6.27 to 85.59 events per 100 000 persons in Manitoba and the territories combined, respectively. During T1, the national (excluding Quebec) weekly hospitalization rate decreased from a pre-pandemic level of 12.82 (95% CI: 12.14 to 13.50) to 5.11 (95% CI: 3.80 to 6.41) events per 100 000 persons. There was no statistically significant change in the mental health and addiction- related hospitalization rate across provinces and territories in T2 compared to T0. However, there was a significant increase in the rate of self-harm-related hospitalizations among females Canada-wide and in most provinces during this period.

Conclusion: Although several Canadian studies have reported increases in mental health and addiction-related outpatient and emergency department visits among youth during the COVID-19 pandemic, this did not correspond to an increase in the inpatient hospital burden, with the notable exception of self-harm among young females.