Illness perception, family resilience, and emotional distress among hospitalized older adults with multimorbidity in Xinjiang, China: a latent profile and mediation analysis.

Mental health conditions are among the most significant, fastest growing, and most inequitably distributed contributors to the global burden of disease. The World Health Organization's (WHO) World Mental Health Report (, , ) estimated that approximately one billion people worldwide live with a mental health condition, with depressive and anxiety disorders alone accounting for over 970 million prevalent cases. The Global Burden of Disease Study 2021 documented that the age-standardized prevalence of mental disorders increased by 4.74% per year between 2019 and 2021, driven largely by the COVID-19 pandemic, and projected continued increases, particularly among those under 24 years of age, through 2050 (). The economic costs are equally alarming: untreated mental illness costs the global economy over USD 1 trillion annually in lost productivity, a figure projected to escalate to USD 6 trillion by 2030 without decisive action (). This burden falls most heavily on the Global South—low- and middle-income countries (LMICs) in sub-Saharan Africa, South and Southeast Asia, Latin America and the Caribbean, and the Middle East and North Africa—which account for approximately 81% of global mental health disability-adjusted life years (DALYs) yet receive less than 10% of global mental health resources (). The mental health treatment gap, the proportion of people with mental health conditions receiving no care, exceeds 75% across most of Latin America and the Caribbean (), surpasses 85% in many Asian LMICs, and can exceed 90% for common mental disorders in parts of sub-Saharan Africa (). In the African region alone, an estimated 10% of the population lives with a mental disorder, yet fewer than one in 10 receives any treatment (). These figures represent not simply a health crisis but a human rights emergency with profound developmental consequences. The growing burden in the Global South is driven by a convergence of structural determinants. Poverty and economic insecurity are among the most robust predictors of the prevalence of mental disorders (). Armed conflict and forced displacement—geographically concentrated in LMICs—generate significant and enduring mental health sequelae, including post-traumatic stress disorder (PTSD), depression, and anxiety (, ). Climate change and natural hazards disproportionately affect developing countries while generating significant mental health burdens (). The COVID-19 pandemic created an estimated 28% increase in major depressive disorders and a 26% increase in anxiety disorders globally in 2020 alone, with the greatest impact in countries with the weakest pre-existing mental health systems (, , ).