“Our findings show that mental disorder burden peaks among 15 – 19-year-olds, which is a critical developmental period that can shape trajectories for education, employment, and relationships,” said Dr. Alize Ferrari, a co-author of a major new study in The Lancet. For a family with a teenager at home, that sentence lands close.
The research, announced on May 21, 2026 by the Institute for Health Metrics and Evaluation in Seattle, was done with the University of Queensland. Nearly 1.2 billion people worldwide were living with a mental disorder in 2023, almost double the number in 1990. Mental disorders have become the leading cause of disability globally, overtaking heart disease, cancer and bone-and-muscle conditions.
How big the study was
The team looked at 12 mental disorders across 25 age groups, 21 regions and 204 countries and territories from 1990 to 2023. Nothing broader has been done on this subject to date, according to the release. Anxiety disorders and major depressive disorder ranked 11th and 15th in burden among 304 diseases and injuries. In 2023 mental disorders accounted for 171 million disability-adjusted life years, making them the fifth-leading cause of total disease burden. They also made up more than 17% of all years lived with disability.
Anxiety and depression drove the recent rise. Since 2019, age-standardized rates of major depressive disorder have climbed about 24%, and those of anxiety disorders more than 47%. Both peaked in the years after the COVID-19 pandemic.
Who carries the load
The burden rises with age through childhood. In early childhood the most common conditions are autism spectrum disorder, ADHD, conduct disorder and developmental intellectual disability, and boys are affected more often than girls. By adolescence anxiety and depression take the lead. They help explain why the load peaks at 15 to 19.
Women are hit harder across age groups. In 2023, 620 million women were living with a mental disorder, against 552 million men. Women accounted for 92.6 million DALYs and men for 78.6 million. The researchers point to domestic violence and sexual abuse, heavier caregiving duties and gender discrimination as likely factors.
Burden grew in every region between 1990 and 2023. Some of the highest rates were in Australasia and Western Europe, in countries including the Netherlands, Portugal and Australia. Large increases also showed up in Western sub-Saharan Africa and parts of South Asia.
Why now? “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 Dr. Damian Santomauro of the University of Queensland. Coverage by Reframed.News added that better detection and diagnosis may also play a part.
The treatment gap
Here the numbers turn sobering. Only about 9% of people with major depressive disorder worldwide receive even minimally adequate treatment, and fewer than 5% do in 90 countries. Just a handful of high-income settings, among them Australia, Canada and the Netherlands, have coverage above 30%. The authors say expanding services, above all in low- and middle-income countries, will be critical.
A teenager who seems withdrawn, anxious or low for weeks should see a doctor, and families can start there.
Sources
- Global mental disorders have nearly doubled since 1990, now affecting 1.2 billion people worldwide | Institute for Health Metrics and Evaluation
- Lancet study says mental disorders are now the leading global cause of years lived with disability (Reframed.News)
- Mental Disorders Global Impact: Key Findings (Knowridge)
