Background: Research points to a high depression burden among youth during the COVID-19 pandemic; however, a lack of systematic evidence exists. We determine the change in depression symptoms among children and adolescents during COVID-19 compared to pre-pandemic baselines. By using country differences in pandemic-related restrictions and school closures in Europe as quasi-experimental design, we evaluate policy impacts on depression. Methods: In this systematic review and meta-analysis, following the PRISMA statement, we searched six databases (MEDLINE, EMBASE, PsycINFO, Cochrane Central, Web of Science, WHO COVID-19) using a peer-reviewed search string up until March 18, 2022 with citation tracking and grey literature searches. No limitations regarding language and effect measures existed. We included studies that compared (1) general depression symptoms or (2) clinically relevant depression rates in children and adolescents (≤ 19 years) before and during the COVID-19 pandemic in Europe. The validated Oxford Stringency Index was used as indicator for pandemic-related restrictions. Screening for eligibility, extracting data from published reports and from unpublished data requested directly from study authors, assessing the study risk of bias and grading certainty of evidence using the GRADE approach, were all done in duplicate. Data were pooled in a random-effects model. PROSPERO: CRD42022303714. Results: Of 7,422 nonduplicate records, 22 studies with data from 868,634 participants pre-pandemic and 807,480 during pandemic, met full inclusion criteria. For the comparison of depression symptoms before and during the COVID-19 pandemic, moderate certainty of evidence was observed for general depression symptoms (standardized mean difference, 0.21 [95%CI, 0.12–0.30]; I² = 94%) and low certainty of evidence for clinically relevant depression rates (odds ratio, 1.36 [95%CI, 1.05–1.76]; I² = 95%) for total population. Increase in general depression symptoms was higher for male adolescents, whereas increase in clinically relevant depression rates was higher for females. Effect estimates were significantly higher when pandemic-related restrictions were more stringent or school closure occurred. Conclusion: An increase in depression symptoms occurred in a pre-pandemic vs. during-pandemic comparison within the COVID-19 pandemic, whereby pandemic-related restrictions (such as school closures) resulted in a considerable effect increase. Ensuring adequate supply of mental health recovery services and long-term monitoring is of high public health relevance.

Background: Considering the heterogenous evidence, a systematic review of the change in anxiety in European children and adolescents associated with the COVID-19 pandemic is lacking. We therefore assessed the change compared with pre-pandemic baselines stratified by gender and age as well as evaluated the impact of country-specific restriction policies. Methods: A registration on the ‘International Prospective Register of Systematic Reviews’ (PROSPERO) occurred and an a priori protocol was published. We searched six databases (PubMed, Embase, PsycINFO, Cochrane Central Register of Controlled Trials, Web of Science, WHO COVID-19) using a peer-reviewed search string with citation tracking and grey literature screening. Primary outcomes were: (1) general anxiety symptoms; and (2) clinically relevant anxiety rates. We used the Oxford COVID-19 Stringency Index as an indicator of pandemic-related restrictions. Screening of title/abstract and full text as well as assessing risk of bias (using the ‘Risk of Bias in Non-randomized Studies of Exposure’ [ROBINS-E]) and certainty of evidence (using the ‘Grading of Recommendations Assessment, Development and Evaluation’ [GRADE]) was done in duplicate. We pooled data using a random effects model. Reporting is in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) statement. Results: Of 7,422 non-duplicate records, 18 studies with data from 752,532 pre-pandemic and 763,582 pandemic participants met full inclusion criteria. For general anxiety symptoms the total change effect estimate yielded a standardised mean difference (SMD) of 0.34 (95% confidence interval [CI], 0.17–0.51) and for clinically relevant anxiety rates we observed an odds ratio of 1.08 (95%-CI, 0.98–1.19). Increase in general anxiety symptoms was highest in the 11–15 years age group. Effect estimates were higher when pandemic-related restrictions were more stringent (Oxford Stringency Index > 60: SMD, 0.52 [95%-CI, 0.30–0.73]) and when school closures (School Closure Index ≥ 2: SMD, 0.44 [95%-CI, 0.23–0.65]) occurred. Conclusion: General anxiety symptoms among children and adolescents in Europe increased in a pre/during comparison of the COVID-19 pandemic; particularly for males aged 11–15 years. In periods of stringent pandemic-related restrictions and/or school closures a considerable increase in general anxiety symptoms could be documented. PROSPERO registration: CRD42022303714.

Background: Emerging research suggests that physical activity among children and adolescents decreased during the COVID-19 pandemic. However, a differentiated overview of European youth is lacking. In particular, no systematic analysis has been conducted to date on the impact of heterogeneous pandemic restrictions and school closures within European countries, and with regard to potentially vulnerable groups. Methods: We searched seven databases and included studies for children and adolescents (≤ 19 years) of the WHO European Region that compared physical activity during the COVID-19 pandemic with a pre-pandemic baseline using validated measurement instruments. We used the Oxford Stringency Index and School Closure Index as indicators of restriction stringency. Screening for eligibility, data extraction, assessment of the study risk of bias (using the ‘Risk of Bias in Non-randomized Studies - of Exposure’ [ROBINS-E]) and certainty grading of evidence (using the GRADE approach), were all done in duplicate. Unpublished data was requested from study authors. Data were pooled in random effects models. An a priori protocol was published, reporting is carried out in accordance with the ‘Preferred Reporting Items for Systematic Review and Meta-Analyses’ (PRISMA) statement. Results: Of 14,897 non-duplicate records, 26 publications (n = 15,038 pre-pandemic, n = 13,041 during pandemic) met full inclusion criteria. Comparison before and during the COVID-19 pandemic revealed a significant reduction in total physical activity (standardized mean difference [SMD], -0.57 [95%CI, -0.95; -0.20]) and moderate-to-vigorous physical activity (SMD, -0.43 [95% CI, -0.75; -0.10]), corresponding to a decrease of 12 min per day (a 20% reduction of the WHO recommendation). A decrease in sporting activity was also recorded. Subgroup analyses suggested that middle childhood (aged 8–12) and adolescents were particularly affected by the decline. School closures were associated with a reduction in physical activity. The certainty of evidence for all outcomes was low. Conclusions: A sharp decline in all forms of physical activity was recorded among European children and adolescents during the COVID-19 pandemic. This decline was higher during periods of school closure and mainly affected younger schoolchildren and adolescents. Immediate action by policy-makers and practitioners, as well as evidence-based public health strategies, are imperative in reversing this trend. Trial registration: PROSPERO: CRD42023395871

Physical fitness is a key indicator of current and future health in children and adolescents. Evidence suggests that fitness levels have declined then stagnated in recent decades, but it remains unclear how the coronavirus disease 2019 (COVID-19) pandemic has impacted this trend. We conducted a systematic review and meta-analyses to assess pandemic-related changes in physical fitness among children and adolescents (0-19 years) in the World Health Organization European Region. Seven databases were searched up to February 28, 2025 for studies reporting validated pre- and during/post-pandemic fitness measurements. Two reviewers independently performed screening, data extraction, risk-of-bias assessment (Risk Of Bias In Non-randomized Studies - of Exposure; ROBINS-E), and certainty grading (Grading of Recommendations, Assessment, Development and Evaluation; GRADE). Random-effects meta-analyses yielded standardized mean differences (SMDs) with 95% confidence intervals (95%CIs). Subgroup analyses examined sex, age, year, and national restriction severity (Oxford Stringency Index). Thirty-two studies comprising 270,179 participants and 1,519,386 fitness measurements from 17 European countries were included. Cardiorespiratory fitness declined significantly during the pandemic, especially in 2021, with reductions in endurance (SMD = -0.43; 95%CI: -0.61 to -0.25) and speed (SMD = -0.29; 95%CI: -0.61 to 0.03). While speed returned to baseline by 2023, endurance remained below pre-pandemic levels (SMD = -0.10; 95%CI: -0.12 to -0.08). Girls and adolescents were disproportionately affected. In contrast to cardiorespiratory fitness, muscular fitness remained largely unchanged. Stricter national regulations were associated with greater declines in cardiorespiratory fitness. COVID-19 pandemic restrictions were associated with a marked decline in cardiorespiratory fitness in European children and adolescents, with levels not recovered by 2023. These findings call for urgent, targeted public health interventions to improve physical fitness and prevent long-term health consequences.

Background: A growing number of studies point to a high mental health burden among children and adolescents during the COVID-19 pandemic, particularly concerning anxiety. However, the study quality and effect direction are heterogeneous in the existing primary studies with a lacking overview for the European continent. Therefore, this systematic review aims to critically synthesise the evidence regarding the impact of the COVID-19 pandemic on anxiety among children and adolescents in Europe compared to a pre-pandemic baseline. Methods: A systematic literature search will be performed in six databases (MEDLINE, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials, Web of Science, and WHO COVID-19 database) with a peer reviewed search strategy according to the evidence-based checklist Peer Review of Electronic Search Strategies (PRESS). Inclusion criteria are children and adolescents ≤ 19 years living in Europe and data report during the COVID-19 pandemic with an appropriate pre-pandemic baseline. Primary outcomes are general anxiety symptoms and clinically relevant anxiety rates. Risk of bias will be assessed using the ‘Risk of Bias in Non-randomised Studies of Exposure’ (ROBINS-E). Data extraction will systematically include information on study design, population characteristics, COVID-19 determinants, pre-pandemic baseline, diagnostic instruments and outcome. The certainty of evidence for each outcome will be evaluated by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach adapted to the use of non-randomised studies. All process steps will be performed independently by two reviewers; any discrepancies will be discussed and, if necessary, resolved by a third author. Also, subgroup analysis, sensitivity analysis, publication bias analysis, and meta-regression analysis, if applicable, will be performed. The systematic review was registered in the Prospective Register of Systematic Reviews (PROSPERO) and the protocol was prepared in accordance to the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) statement. Discussion: This systematic review will address the lack of a critical and comprehensive summary of findings on the COVID-19 pandemic impact on anxiety among children and adolescents in Europe. In addition, it aims to identify pandemic-policy differences, such as the effect of school-closures, and identify particularly vulnerable risk groups. Systematic review registration: CRD42022303714 (PROSPERO).