A new global study has revealed a dramatic rise in mental health disorders worldwide, with more than one billion people estimated to be living with mental illnesses in 2023, marking a 95.5 per cent increase since 1990.
The study, published in The Lancet and led by the Institute for Health Metrics and Evaluation, analysed data from 204 countries as part of the 2023 Global Burden of Diseases, Injuries, and Risk Factors Study.
Researchers assessed a broad range of mental disorders, including depression, anxiety disorders, bipolar disorder, autism spectrum disorder, attention deficit hyperactivity disorder (ADHD), schizophrenia, anorexia nervosa, bulimia nervosa, conduct disorder, dysthymia, and developmental intellectual disability.
According to the findings, global cases of mental disorders rose from an estimated 599 million in 1990 to 1.17 billion in 2023.
Anxiety disorders and major depressive disorders emerged as the most common conditions globally. Anxiety disorder cases increased from 182 million in 1990 to 470 million in 2023, while major depressive disorders rose from 102 million to 236 million within the same period.
Although anorexia, bulimia, and schizophrenia recorded lower case numbers, the study noted that they remained significant public health concerns, affecting approximately four million, 14 million, and 26 million people respectively in 2023.
The report further showed gender disparities in mental health patterns. Most mental disorders were found to be more common among females, while autism, conduct disorders, ADHD, personality disorders, and unexplained intellectual disability were more prevalent among males.
Co-author of the study, Alize Ferrari, explained that adolescence remains a particularly vulnerable stage for mental health development.
“Our findings show that mental disorder burden peaks among 15–19-year-olds, which is a critical development period that can shape trajectories for education, employment, and relationships,” Ferrari said.
Researchers also highlighted the lasting effects of the COVID-19 pandemic on mental health globally. While anxiety and depression rates were already increasing before the pandemic, the study found that depression worsened during the crisis and has yet to return to pre-pandemic levels. Anxiety levels also remained elevated through 2023.
The study measured disability-adjusted life years (DALYs), an indicator representing years of healthy life lost due to illness or disability. Mental disorders rose from the 12th leading cause of DALYs globally in 1990 to the fifth leading cause in 2023.
Anxiety and major depressive disorders ranked among the top 20 causes of DALYs in 152 of the 204 countries analysed. Despite lower prevalence rates, schizophrenia accounted for the third-highest burden of mental disorder DALYs globally because of its severity.
Women recorded a higher overall burden of mental illness, with 92.6 million DALYs compared to 78.6 million among men.
The researchers called for stronger mental health surveillance systems, particularly in low- and middle-income countries, alongside coordinated policies focused on prevention, early treatment, and support tailored to differences in age and gender.
“Responding to the mental health needs of our global population, especially those most vulnerable, is an obligation, not a choice,” the study concluded.
