Adolescence is a critical developmental period during which many mental and substance use disorders first emerge, yet global estimates remain limited. Using data from the Institute for Health Metrics and Evaluation for the Global Burden of Disease Study 2021, we examined prevalence among adolescents aged 10–19 years across 204 countries. In 2021, 15.2% had at least one mental disorder. Anxiety disorders were most prevalent (4.9%), followed by conduct disorder (2.7%), ADHD (2.6%), and depressive disorders (2.4%), with major depressive disorder affecting 2.0%. Autism spectrum disorders accounted for 0.9%, intellectual disability 1.7%, bipolar disorder 0.3%, and eating disorders 0.3% (anorexia 0.1%, bulimia 0.2%). Schizophrenia (0.04%) and other disorders (0.2%) contributed smaller fractions. Substance use disorders affected 0.8%, mainly drug use (0.5%) and alcohol (0.3%), with cannabis use disorders at 0.4%. Prevalence varied by sex, region, and socio-demographic development: females showed higher internalizing conditions, males higher externalizing disorders. High-SDI regions had highest prevalence (20.7%) versus low-SDI (13.4%); High-Income North America recorded 22.8%, South Asia 9.7%, and Sub-Saharan Africa 11.6%, likely reflecting under-recognition, stigma, and limited diagnostic capacity. These findings highlight the global significance of adolescent mental health, disparities across sexes and regions, and the need for context-specific prevention and treatment strategies.
Castaldelli-Maia et al. (2025) studied this question.