Study data published in The Lancet describe the psychiatric effects of the COVID-19 pandemic on a global scale. Per a systematic review of studies conducted in 204 countries and territories, the global prevalence rates of depressive and anxiety disorders increased significantly during the pandemic compared with the prior year. Younger individuals, women, and patients with existing psychiatric conditions experienced the greatest increases in prevalence rates.

Investigators conducted a systematic review of studies published between January 1, 2020 and January 29, 2021 that estimated the prevalence of major depressive disorder and anxiety disorders during the COVID-19 pandemic. Authors searched PubMed, Google Scholar, preprint servers, grey literature sources, and consulted with psychiatry experts. Meta-regression models were used to estimate the change in prevalence rates between the prepandemic and midpandemic periods while adjusting for certain COVID-19 impact indicators, including human mobility, daily infection rate, and excess mortality.

Human mobility data were extracted from estimates produced by Institute for Health Metrics and Evaluation COVID-19 Forecasting Team. Global prevalence rates were estimated for both depression and anxiety disorders; disability-adjusted life years (DALYs) were also calculated.

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A total of 48 studies were included in the meta-analysis and 46 of these studies assessed depression and 27 assessed anxiety disorders. A search for prepandemic baseline prevalence rates yielded an additional 11 studies on depression and 7 studies on anxiety. The majority of included studies were conducted in Western Europe (n=22) and North America (n=14), with the remaining trials published in Australia, Asia, and central Europe.

Reduced human mobility during the pandemic was associated with increased rates of major depressive disorder (P =.02) and anxiety disorders (P =.022). Increased SARS-CoV-2 infection rate was also significantly associated with depressive (P =.0005) and anxiety (P <.0001) disorders. As such, subsequent meta-analyses were adjusted for human mobility and SARS-CoV-2 infection rates.

In adjusted regression models, age, sex, and comorbid prepandemic symptoms were each significantly associated with increased depression and anxiety rates. Compared with men, women experienced greater increases in depression and anxiety during the pandemic (both P =.0001). However, both men and women experienced surging prevalence rates during the pandemic period.

Compared to older adults, younger age groups experienced more significant increases in depression and anxiety rates (both P =.0001). Finally, patients with comorbid depressive and anxiety symptoms were subject to greater increases than patients without these comorbidities (P =.008).

Worldwide, the COVID-19 pandemic resulted in an estimated 53.2 (95% CI, 44.8-62.9) million additional cases of major depressive disorder, constituting an increase of 27.6% (25.1-30.3%) from the prepandemic year. Similarly, an additional 76.2 million (64.3-90.6) cases of anxiety disorders were estimated to have occurred during the pandemic, for an increase of 25.6%.

During the pandemic period, the estimated global prevalence rates of depression and anxiety were 3152.9 (2722.5-3654.5) and 4802.4 (4108.2-5588.6) cases per 100,000 individuals. Regions with greater COVID-19 transmission appeared to experience greater increases in prevalence rates. Together, depression and anxiety disorders caused approximately 49.4 (33.6-68.7) million and 44.5 (30.2-62.5) DALYs globally during 2020.

These data illustrate the exacerbating effect of COVID-19 on the worldwide mental health burden. For study limitations, investigators noted that data on psychiatric disorders were not available in parts of South America and Africa. As such, calculated prevalence rates may not appropriately represent the burden of depression and anxiety in these regions. Further, the retrospective study design prevents the assertion of causality. While COVID-19 certainly affects psychiatric wellbeing, a myriad of other factors likely came into play but remained unmeasured.

“This pandemic has created an increased urgency to strengthen mental health systems in most countries,” the investigators wrote.

“Mitigation strategies could incorporate ways to promote mental wellbeing and target determinants of poor mental health and interventions to treat those with a mental disorder.”

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 


Santomauro DF, Mantilla Herrera AM, Shadid J, et al. COVID-19 Mental Disorders Collaborators. Global prevalence and burden of depressive and anxiety disorders in 204 countries and territories in 2020 due to the COVID-19 pandemic. Lancet. Published online October 8, 2021. doi:10.1016/S0140-6736(21)02143-7