Inequality of Adolescents’ Mental Health between 2018 and 2023: Repeated Cross-sectional Evidence from COMPASS

Background The COVID-19 pandemic has disrupted adolescents' lifestyles, negatively impacting their mental health and well-being. To date, few studies have examined the medium- to long-term consequences for adolescents. This study examines the evolution of adolescents’ mental health using data collected between 2018 and 2023 from a population of adolescents living in Quebec, Canada, with a focus on depressive symptoms, anxiety symptoms, and flourishing scores. It also explores whether specific demographic and socioeconomic groups are disproportionately affected. Methods We used data collected as part of the COMPASS study from students attending a cohort of 31 high schools in Quebec (Canada). We conducted a repeated cross-sectional analysis from 2018–2023 involving approximately 13,500 adolescents aged 12–17 years each year. The mental health indicators included the Center for Epidemiologic Studies Depression Scale Revised (CESD-R-10), the Generalized Anxiety Disorder scale (GAD-7), and the Diener Flourishing Scale. Statistical analyses employed techniques adapted from the Foster-Greer-Thorbecke indices, establishing a minimum threshold for optimal mental health. We examined various metrics, including the prevalence of mental health issues; the average gap and inequality gap from the threshold of adolescents reporting depressive symptoms, anxiety symptoms or positive flourishing score; and a measure of mental health inequality inspired by the Gini coefficient. Results The prevalence of depressive symptoms and anxiety symptoms increased during the pandemic, peaking in 2021 and 2022, respectively, before returning close to pre-pandemic levels in 2023. However, flourishing scores continued to decline throughout the study period. Anxiety symptoms show greater inequalities than the other two indicators. Girls, older adolescents, and those from more deprived backgrounds presented poorer mental health, with significant disparities persisting post-pandemic. Gender disparities in mental health have widened both during and after the pandemic. Discussion This study reveals that indicators representing positive and negative constructs of mental health evolve differently over time. While depression and anxiety symptoms gradually returned to prepandemic levels, fewer adolescents reported positive flourishing scores over time, emphasizing the urgency of implementing innovative programs that promote holistic well-being, including having positive relationships, feelings of competence, and meaning and purpose in life.