麻豆传媒

Depressive and anxiety disorders increased substantially around the world since the start of the pandemic, hitting some groups harder than others, according to a new systematic review and meta-analyses.

Two proxy measures for the impact of COVID-19 -- daily infection rates and reductions in human mobility -- were both significantly associated with surges in major depressive disorder (regression coefficient [B] 18.1, 95% uncertainty interval [UI] 7.9-28.3; and B 0.9, 95% UI 0.1-1.8; respectively), reported Damian Santomauro, PhD, of Queensland Centre for Mental Health Research in Australia, and colleagues.

The daily COVID-19 infection rate and drops in human mobility were also both significantly tied with anxiety disorder prevalence (B 13.8, 95% UI 10.7-17.0; B 0.9, 95% UI 0.1-1.7, respectively), the authors wrote in .

However, daily COVID-19 mortality rates were not associated with changes in prevalence for either disorder, the researchers found.

Looking more closely, those who identified as female endured a greater toll on their mental health during the pandemic than men (B 0.1, 95% UI 0.1-0.2 for major depressive disorder; B 0.1, 95% UI 0.1-0.2 for anxiety disorders). Likewise, younger age groups also had a higher prevalence of both depressive disorder (B -0.007, 95% UI -0.009 to -0.006) and anxiety disorders (B -0.003, 95% UI -0.005 to -0.002) compared with older populations.

On top of that, areas around the world that were the hardest hit by the pandemic saw the largest spikes in new cases. Leading the list was South Asia, followed by North Africa and the Middle East, and Latin America and the Caribbean.

After identifying and analyzing data from sources that met their inclusion criteria -- 46 for major depressive disorder and 27 for anxiety disorders -- the researchers were able to estimate that depression rose worldwide by 53.2 million cases, equating to an increase of 27.6% due to the pandemic. This spike brought the total global prevalence for major depressive disorder to 3,153 cases per 100,000 population.

As for anxiety disorders, an estimated 76.2 million new cases were brought on by the pandemic, corresponding to somewhere between a 64.3% to 90.6% spike in cases. These new cases brought the total global prevalence of anxiety disorders to approximately 4,802 cases per 100,000 population.

For both disorders, Santomauro's group used final prevalence estimates and disability weights to calculate disability-adjusted life-years (DALYs). All in all, major depressive disorder and anxiety disorder caused 49.4 million DALYs and 44.5 million DALYs around the world, respectively, in the year 2020 alone.

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the authors searched for peer-reviewed sources published from Jan. 1, 2020 to Jan. 29, 2021. Studies were eligible only if they reported anxiety and depression prevalence during the COVID-19 pandemic, plus a pre-pandemic baseline. Changes in human mobility were calculated through a composite of mobile phone data provided by sources such as Facebook, Google, and Descartes Labs, paired with data on physical distancing mandates.

Despite their findings, the authors emphasized that neither daily infection rate nor decreasing human mobility should be interpreted as risk factors for major depressive disorder or anxiety disorders.

"The COVID-19 pandemic is occurring against a complex backdrop of a range of social determinants of mental health, as well as well-known inequalities within these determinants," they wrote.

On the higher prevalences for women, Santomauro's group stated that this result "was anticipated because females are more likely to be affected by the social and economic consequences of the pandemic." Similarly, the higher frequency of these mental health disorders among young people may be attributed to the pandemic's significant impact on global education, which led approximately 1.6 billion learners from 190 countries to be partially or entirely taken out of school.

For countries that had no available survey data on depression or anxiety, the authors used a "leave-one-country-out" cross-validation approach to assess the generalizability of their estimates. However, in both the article and in the by Maxime Taquet, PhD, of the University of Oxford in England, and colleagues, it was noted that one of the study's major limitations was the overall lack of data on mental health prevalence in many parts of the world, like South America and Africa.

Another limitation, both parties acknowledged, was that the mental health data that were available were all based on self-report scales measuring symptoms rather than actual diagnoses. At a time when COVID-19 is spreading rampantly, it is natural for more people to report experiencing higher levels of worry or distress over possible infection or the sickness of a loved one. These natural emotions, they added, may not constitute a formal anxiety disorder diagnosis.

"The findings of this study should urgently incentivize more research to determine the fuller geographical distribution of depression and anxiety disorders, the prevalence of depressive and anxiety disorders, and the underpinning mechanisms to improve mental health in the context of the COVID-19 pandemic globally," Taquet's group concluded.

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