The world's burden of mental disorders have more than doubled since 1990, and they are now the leading cause of disability globally, overtaking cardiovascular disease, cancer and musculoskeletal conditions, according to a new study published in The Lancet journal.

Researchers from The University of Queensland and Queensland Centre for Mental Health Research (QCMHR) in Australia and the US' University of Washington found that nearly 1.2 billion people worldwide were living with a mental disorder in 2023, nearly double the number in 1990.

The increase was largely driven by rising numbers of anxiety and depression, and people aged 15-19 and women are disproportionately impacted, they said.

In 2023, 620 million women of all ages were living with a mental disorder compared to 552 million men of all ages globally. Mental disorders also accounted for more than 17 per cent of all years lived with disability worldwide.

In India, age-standardised prevalence of anxiety disorders across both sexes was almost 2,592 per one lakh population in 1990, which rose by 123.5 per cent to 5,793 per one lakh population in 2023. Prevalence of the disorders increased among women by 136.7 per cent during 1990-2023, compared to 102 per cent among men.

"These rising trends may reflect both the lingering effects of pandemic-related stress and longer-term structural drivers such as poverty, insecurity, abuse, violence, and declining social connectedness," said first author Damian Santomauro, associate professor at the Queensland Centre for Mental Health Research in partnership with the University of Queensland.

"Addressing this growing challenge will require (a) sustained investment in mental health systems, expanded access to care, and coordinated global action to better support populations most at risk," Santomauro said.

Trends from the Global Burden of Diseases, Injuries, and Risk Factors Study 2023 were analysed for 12 mental disorders, including anxiety disorders, major depression, bipolar disorder, schizophrenia, autism spectrum disorders, ADHD, and eating disorders.

The team said that regardless of the health sources available, mental disorders imposed a significant health burden across countries and territories in 2023. The burden has increased over time and a stronger surveillance is required, especially in low and middle-income countries, they said.

Women experienced higher rates of anxiety and depression in 2023, while neurodevelopmental and behavioural disorders such as attention deficit hyperactivity disorder (ADHD), conduct disorder, and autism are more common in males and tend to peak in adolescence.

Globally, the highest burden was found in the 15-19 age group, underscoring the urgent need for early prevention and targeted support for young people.

In September 2025, the World Health Organization released a report estimating that more than a billion people globally were living with a mental health condition in 2021, with anxiety and depressive disorders accounting for two-thirds of all cases.

Databases 'Global Health Estimates 2021' -- managed by the WHO -- and 'Global Burden of Diseases, Injuries and Risk Factors Study 2021' were analysed.

Author Alize Ferrari, from the University of Queensland's school of public health, said the findings show the response to mental disorders globally is not sufficient.

"It doesn't matter whether you're from a resource poor country, or a country with more health resources available, the burden is high," Ferrari said, adding that while more research is required, factors including data quality and availability are likely contributing to the global trends.

"There are also risk factors for mental disorders likely at play including those related to child maltreatment, domestic violence, genetics, rising inequality, decline in social cohesiveness, impact of climate change, pandemics, war and natural disasters," Ferrari said.