Impact of the COVID-19 pandemic on the mental health of children and adolescents: A systematic review and meta-analysis of longitudinal studies

Children's and adolescents' mental health has been affected since the onset of the coronavirus disease (COVID-19) pandemic, receiving global attention. We conducted a systematic review and meta-analysis of longitudinal studies to assess the extent of the mental health changes of children and adolescents in the aftermath of the pandemic. We searched PubMed, Embase, Web of Science, and PsycINFO to explore the pandemic's impact on children and adolescents' mental health; longitudinal studies were included. We used the random effects model to estimate the standardized mean differences (SMD) with 95 % confidence intervals (CI). Twenty articles were included. Results showed that there was an increase in anxiety (SMD = 0.18, 95 % CI 0.05–0.32) and depressive symptoms (SMD = 0.22, 95 % CI 0.13–0.32) in children and adolescents after the pandemic. Anxiety and depressive symptoms noticeably increased from April to May 2020, subsequently decreased, but saw a small resurgence during the second wave of the pandemic. Anxiety change varied by region; highest in Asia (SMD = 0.38, 95 % CI 0.25–0.51). Heterogeneity was high in this study, with high variability in psychiatric symptoms among individuals. This study on changes in children's and adolescents' mental health, anxiety and depression symptoms showed varying degrees of deterioration. Changes in symptoms were influenced by time and region and showed fluctuations.