Incidence, prevalence, and global burden of attention-deficit/hyperactivity disorder from 1990 to 2021 across 204 countries in individuals under age 20: data, with critical appraisal, from the 2021 Global Burden of Disease study

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition in children and young people worldwide. Robust estimates of its incidence, prevalence, and burden are essential for informing public health policy and planning. Using data from the Global Burden of Disease Study 2021 (GBD 2021), this global population-based analysis assessed ADHD among individuals under 20 years of age across 204 countries and territories from 1990 to 2021. The study examined incidence, prevalence, and disability-adjusted life years (DALYs) associated with ADHD. In 2021, there were an estimated 46,890,733 (95% uncertainty interval [UI]: 32,136,904-67,271,064) prevalent cases and 4,111,621 (2,775,203-5,954,941) incident cases globally in individuals under 20 years. ADHD accounted for 574,979 (294,277-977,557) DALYs, with a global prevalence rate of 1.78% (1.22-2.55%) and an incidence rate of 0.16% (0.11-0.23%). The global DALY rate was 21.8 (11.2-37.1) per 100,000 population. Prevalence and incidence were highest in Australia, with rates of 5.62% (4.16-7.46%) and 0.49% (0.34-0.66%), respectively. Between 1990 and 2021, global prevalence and incidence rates decreased modestly by 6.0 and 5.81%, respectively. Across all GBD regions, prevalence was higher in males than females (2.52 vs 0.99%) and increased with higher socio-demographic index levels. Overall, the GBD 2021 study provides the most comprehensive global estimates of ADHD burden in young people. These findings are important for guiding policymakers and stakeholders, although potential methodological limitations suggest that the prevalence, incidence, and burden of ADHD may be underestimated.