Out of concern that the stressors of the COVID-19 pandemic would exacerbate the already-high prevalence of depressive and anxiety disorders, experts around the world collaborated on a massive data collection and analysis effort. The scientists recognised that in addition to the physical health effects of the disease (widespread illness and death), the pandemic also had an impact on many determinants of mental health through social restrictions, lockdowns, school and business closures, loss of livelihood, decreases in economic activity, and more, all of which have a greater impact on people with fewer advantages. In the interest of timely and effective health system responses, the COVID-19 Mental Disorders Collaborators wanted to provide information about the impact of the pandemic on mental health internationally, considering differences by age, sex, and location.
This study is part of the larger Global Burden of Diseases, Injuries, and Risk Factors Study, which has shown that mental health disorders are among the leading causes of the global health burden, and that major depressive disorder and anxiety disorders are the two most disabling mental disorders. Both major depressive disorder and anxiety disorders increase the risk of other diseases and suicide.
The researchers conducted a thorough and systematic review of data that reported on the prevalence of major depressive disorder and anxiety disorders during the COVID-19 pandemic, published between Jan 1, 2020, and Jan 29, 2021. They searched PubMed, Google Scholar, preprint servers, grey literature sources, and they also consulted experts.
The scientists used the assembled data in a meta-regression to estimate changes in the prevalence of major depressive disorder and anxiety disorders between pre-pandemic and mid-pandemic via COVID-19 impact indicators (human mobility, daily SARS-CoV-2 infection rate, and daily excess mortality rate). They then used this model to estimate the change from pre-pandemic prevalence (estimated using Disease Modelling Meta-Regression version 2.1 by age, sex, and location). They used final prevalence estimates and disability weights to estimate years lived with disability and disability-adjusted life-years (DALYs) for major depressive disorder and anxiety disorders
The COVID-19 Mental Disorders Collaborators identified 5,683 unique data sources, of which 48 met their rigorous inclusion criteria.
- Two COVID-19 impact indicators were associated with increased prevalence of both major depressive disorders and anxiety disorders: daily infection rates and reductions in human mobility, though excess mortality rates were not associated.
- Females were more affected than males, and younger age groups more than older age groups, for both major depressive disorders and for anxiety disorders.
- Not surprisingly, the locations hit hardest by the pandemic in 2020, as determined by the most decreased human mobility and the highest number of daily infection rates, showed the greatest increases in prevalence of major depressive and anxiety disorders.
- The scientists estimated there were an additional 53.2 million cases of major depressive disorders globally (an increase of 27.6%) due to the COVID-19 pandemic.
- They also estimated an additional 76.2 million cases of anxiety disorders globally (an increase of 25.6%).
- Altogether, major depressive disorder caused 49.4 million disability-adjusted life-years and anxiety disorders caused 44.5 million disability-adjusted life-years globally in 2020.
The COVID-19 Mental Disorders Collaborators found that depressive and anxiety disorders increased by about 25% during 2020 due to the COVID-19 pandemic. In conclusion, the authors stated,
Even before the COVID-19 pandemic, depressive and anxiety disorders featured as leading causes of burden globally, despite the existence of intervention strategies that can reduce their effects. Meeting the added demand for mental health services due to COVID-19 will be difficult, but not impossible. Mitigation strategies should promote mental wellbeing and target determinants of poor mental health exacerbated by the pandemic, as well as interventions to treat those who develop a mental disorder.
Strengths and limitations
I found this an extraordinarily well-designed, well-executed, and well-documented study. It represents a massive collaboration of top scientists from around the world. Their findings are reported in thoughtful and easily-comprehended detail in the paper published in The Lancet and online, explained and illustrated in excellent graphics, charts, and maps.
It’s an important study, published at a time of grave global concern, and deserves to be widely circulated, understood, and implemented.
Implications for practice
Based on their findings of a greatly increased incidence of major mental illnesses, the international group of scientists stated that:
Taking no action cannot be an option.
They observed that health care professionals and legislators should work to ensure that the available mitigation strategies are deployed quickly and effectively, to reduce the enormous additional mental health burden imposed by COVID-19. Limited resources must be deployed strategically, they concluded, considering the local context and vulnerable populations, prioritising inclusivity, stigma reduction, and human rights.
The emphasis going forward should be on promoting population mental health and well-being, targeting determinants of poor mental health that have been exacerbated by the pandemic as well as intervening to treat those who develop a mental disorder.
This collaborative of scientists also recommended public health messaging about the mental health impacts of COVID-19, about optimal management of personal mental health, and pathways to assessment and service access. They have put together a package of resources that include a mixture of digital, telehealth, and face-to-face services that can be tailored to local and individual needs.
Statement of interests
No conflict of interest.
Global prevalence and burden of depressive and anxiety disorders in 204 countries and territories in 2020 due to the COVID-19 pandemic. COVID-19 Mental Disorders Collaborators. The Lancet 2021; 398: 1700–12 Published Online October 8, 2021
GBD 2019 Disease and Injuries Collaborators. Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet 2020; 396: 1204–22.
GBD 2019 Mental Disorders Collaborators. Global, regional, and national burden of mental disorders in 204 countries and territories, 1990–2019: a systematic analysis from the Global Burden of Disease Study 2019. Lancet Psychiatry (in press).
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