The Global Burden of Mental Health
According to the WHO's 2022 report, approximately 970 million people worldwide (12.5% of the population) live with some form of mental disorder. Depression (280 million) and anxiety disorders (300 million) are the most prevalent, having increased by 27.6% and 25.6% respectively in 2020, the first year of the COVID-19 pandemic. Mental disorders account for 4.9% of global disability-adjusted life years (DALYs) and 14.6% of years lived with disability (YLDs) (GBD 2019), making them one of the leading causes of disability burden.
However, international comparison of mental disorder prevalence is extremely difficult. Differences in diagnostic criteria, stigma surrounding mental illness, and disparities in healthcare access mean that reported prevalence rates do not reflect reality. In societies with strong stigma, treatment-seeking rates are low and statistical prevalence is underestimated. "Low reported prevalence" does not necessarily equal "good mental health."
International Comparison of Stress Levels
Gallup's Global Emotions Report (2024) compiles country-level affirmative responses to "Did you experience stress yesterday?" The global average is 41%, with Greece (59%), the Philippines (58%), and Tanzania (55%) highest, and Taiwan (18%), Kazakhstan (19%), and Mongolia (21%) lowest. Japan stands at 43%, roughly at the world average.
Self-reported stress is heavily dependent on cultural context. In cultures that view stress as a sign of weakness, underreporting occurs; in cultures that treat stress as evidence of being busy and productive, overreporting is common. Furthermore, stress from economic hardship and stress from unmet high expectations are qualitatively different but indistinguishable in a single survey question.
Social Connection and Mental Health
Holt-Lunstad et al. (2010), in a meta-analysis, found that people with stronger social relationships had a 50% greater likelihood of survival. This effect size is comparable to that of quitting smoking and exceeds well-known risk factors such as obesity and physical inactivity. Loneliness is not merely an emotion but is thought to affect physical health through heightened inflammatory responses, impaired immune function, and cardiovascular strain.
Japan has attracted international attention as a "loneliness superpower." A Cabinet Secretariat survey conducted in December 2022 (published in 2023) found that about four in ten respondents (40.3%) felt lonely at least occasionally. Rising single-person households, weakening community ties, and long working hours restricting social participation are seen as the background to structural isolation. Japan's 2021 appointment of a "Minister of Loneliness and Isolation" - the second such post in the world, following the UK's creation of the first loneliness minister in 2018 - signals the severity of this problem.
Mental Health and Economic Costs
WHO and World Bank jointly estimate that depression and anxiety disorders cost the global economy $1 trillion annually. This stems primarily from reduced labor productivity (presenteeism) and absenteeism. In Japan, the economic loss from mental disorders is estimated at approximately 2.7% of GDP.
Conversely, investment in mental health generates high returns. WHO estimates that every $1 invested in treating depression and anxiety yields $4 in economic returns through improved productivity. Nevertheless, mental health accounts for only 2.1% of global health budgets on average - small relative to the size of its disease burden.
Ethical Concerns in Ranking Mental Health
Ranking mental health raises unique ethical issues. Unlike physical metrics (height, weight, blood pressure), mental health is intimately bound up with stigma. A display reading "your mental health is in the bottom X% globally" risks reinforcing self-negation in those already struggling.
MyRank's decision not to rank mental health directly reflects this ethical consideration. Instead, it ranks protective factors for mental health - sleep duration, exercise frequency, social connectedness - thereby indirectly encouraging improvements in psychological well-being. The power of data should be deployed not to harm but to support behavioral change.