<p>Schizophrenia is a significant neurodevelopmental mental illness. However, research on the trends related to the disease burden of schizophrenia in pediatric and adolescent populations remains limited. This study intends to examine the changes in the burden of schizophrenia among younger individuals from 1990 to 2021, with the objective of identifying areas that require targeted interventions and preventive measures. Data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 were evaluated to report the incidence and prevalence of schizophrenia among individuals aged 10 to 24 years between 1990 and 2021, across global, regional, and national levels. We provided case numbers and rates per 100,000 individuals. Additionally, we examined trends in schizophrenia concerning age, gender, and socio-demographic index (SDI). Average annual percentage changes (AAPC) were calculated, and years with the most significant trends were identified utilizing joinpoint regression analysis. The study cohort was divided into three age categories: 10 to 14 years, 15 to 19 years, and 20 to 24 years. In 2021, the global incidence and prevalence rates of schizophrenia among young adults and adolescents were 25.6 (95% UI, 18.0-35.1) and 105.7 (95% UI, 70.7-147.5) per 100,000 individuals, respectively, reflecting a decline from 26.6 (95% UI, 19.1–35.8) and 110.5 (95% UI, 75.6–152.0) in 1990. Noticeable changes in schizophrenia incidence were found in 1998, 2001, and 2010. By sex, the incidence rate among men has always been higher than that among women. By age groups, the incidence of schizophrenia increased sharply with age. By SDI quintile, countries with low SDI experienced the most significant rise in both incidence and prevalence rates. At the national level, adolescents and young adults aged 10–24 in Australia reported the highest ASIR for schizophrenia, followed by New Zealand and the United States. The most substantial increase in schizophrenia prevalence rate was noted in Tropical Latin America. From 1990 to 2021, the global incidence of schizophrenia among adolescents and young adults followed a significant three-phase trend: an initial decline, followed by an increase from around 2000 to 2010, and a subsequent decrease in recent years. These findings underscore the need for future research and policy efforts to prioritize reducing health disparities and improving mental health outcomes for at-risk populations—particularly young individuals in low SDI regions. Timely detection and intervention remain essential to mitigate the impact of schizophrenia on individuals and society.</p>