Mental disorders remain significant global burden on health

The prevalence of mental disorders has been on the rise and remains a significant leading cause of disease burden worldwide, according to a 30-year global systematic analysis published in The Lancet Psychiatry.

“Mental disorders are increasingly recognized as leading causes of disease burden. To meet the mental health needs of individual countries in a way that prioritizes transformation of health systems, in-depth understanding of the scale of the impact of these disorders is essential, including their distribution in the population, the health burden imposed, and their broader health consequences,” Alize Ferrari, PhD, of the Queensland Centre for Mental Health Research at the University of Queensland, and colleagues wrote.

Ferrari and colleagues sought to measure impact and occurrence on a global, regional and national scale of 12 mental disorders between 1990 and 2019, using several metrics related to quality of life: disability-adjusted life-years (DALYs), years lived with disability (YLDs) and years of life lost (YLLs).

Researchers assessed estimates for prevalence and burden from both men and women within 23 different age groups across 204 countries and territories worldwide. They estimated DALYs as the sum of YLDs and YLLs to premature mortality. Further, they included information analyzed from several databases regarding prevalence, incidence, remission, duration, severity and excess mortality for individual mental disorders. They performed a Bayesian meta-regression analysis to estimate frequency by disorder, age, sex, year and location.

Results showed that mental disorders accounted for 654.8 million estimated cases in 1990 and 970.1 million cases in 2019, an increase of 48.1 percent. Australasia, tropical Latin America, and high-income North America recorded the highest prevalence of mental disorders across all measurements.

The pervasiveness of depressive disorders was high in sub-Saharan Africa, North Africa and the Middle East in addition to Australasia, tropical Latin America, and high-income North America. Bipolar disorder and schizophrenia frequency varied to a lesser extent across all regions.

Depressive disorders ranked the highest among all age groups in the study, with the exception of those from birth to those aged 14 years, where behavioral issues were the leading cause of burden.

A sharp increase in the global number of DALYs due to mental disorders over the course of the study was found, from 80.8 million in 1990 to 125.3 million in 2019, as well as a rise in the percentage of DALYs arising from the same, at 3.1% in 1990 and 4.9% in 2019.

The highest DALY rates were observed in the U.S., Australia, New Zealand, Brazil, Western Europe, sub-Saharan Africa, North Africa and the Middle East. The lowest DALY rates were observed in Southeast Asia, East Asia, high-income Asia Pacific and Central Asia.

Women and girls were found to carry greater burden for depressive disorders, anxiety disorders, and eating disorders than men and boys, while the reverse was true for autism spectrum disorders and ADHD. By the end of the study, 80.6% of the mental disorder burden was shared by those of working age (16 to 65 years), with 9.2% of the remaining burden found in those younger than 16.

“The findings of GBD 2019 emphasize the large proportion of the global disease burden attributable to mental disorders and the global disparities in that burden,” Ferrari and colleagues wrote. Furthermore, there was no evidence of global reduction in the burden since 1990, despite evidence-based interventions that can reduce the burden across age, sex, and geographical locations.”