Global, Regional, and National Trends in the Burden of Anxiety Disorders From 1992 to 2021: An Age–Period–Cohort Analysis Based on the Global Burden of Disease Study 2021

<b>Background:</b> Anxiety disorders pose a considerable global health challenge, ranking as the most prevalent type of mental illness. This study delineates the trends in incidence, prevalence, and years lived with disability (YLDs) for anxiety disorders at global, regional, and national levels between 1992 and 2021, with an emphasis on the independent effects of age, period, and birth cohort. <b>Methods:</b> Incidence, prevalence, and YLDs were selected as burden indicators of anxiety disorders, following the standardized methodologies of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021, with data presented as numerical counts and age-standardized rates (ASRs) per 100,000 population. An age-period-cohort (APC) model was applied to estimate the overall annual percentage change (net drift), annual percentage change within each age group (local drift), and the relative risks associated with age, period, and cohort. <b>Results:</b> From 1992 to 2021, the global age-standardized incidence rate (ASIR), age-standardized prevalence rate (ASPR) and age-standardized YLDs rate (ASYR) for anxiety disorders showed an overall increase. The APC model estimated a global net drift of 0.16% (95% confidence interval [CI]: 0.03%, 0.30%) for incidence, 0.07% (95% CI: 0.02%, 0.12%) for prevalence, and 0.07% (95% CI: 0.01%, 0.12%) for YLDs. Regionally, the highest ASIR, ASPR, and ASYR were recorded in the high SDI region in 2021, with the Region of the Americas (AMR) showing the highest rates across all three metrics. Among 204 countries/territories, Portugal, Brazil, Lebanon, Iran, and Paraguay ranked as the top five highest for ASIR, ASPR, and ASYR. The age effects on incidence, prevalence, and YLDs followed similar global and regional patterns, with risk initially increasing before declining in older age. The most substantial increase in the period risk of incidence from 1992 to 2021 occurred in high SDI and AMR countries, while prevalence and YLDs saw the largest rise in low-middle SDI region and AMR. A steady increase in the risk of incidence, prevalence, and YLDs was observed across successive birth cohorts globally and regionally. <b>Conclusion:</b> The global burden of anxiety disorders demonstrated an overall upward trend, with considerable regional, demographic, and temporal variations. These findings provide critical insights for optimizing resource allocation and developing tailored public health strategies to address anxiety disorders.