We aimed to report an overview of trends in suicide mortality and years of life lost (YLLs) among adolescents and young adults aged 10–24 years by sex, age group, Socio-demographic Index (SDI), region and country from 1990 to 2021 as well as the suicide mortality with age, period and birth cohort effects.

Estimates and 95% uncertainty intervals for suicide mortality and YLLs were extracted from the Global Burden of Diseases Study 2021. Joinpoint analysis was used to calculate the annual percentage change (APC) and average annual percentage change (AAPC) to describe the mortality and rate of YLLs trends. Age, period and cohort model was utilized to disentangle age, period and birth cohort effects on suicide mortality trends.

Globally, suicide mortality and the rate of YLLs among adolescents and young adults both declined from 1990 to 2021 (AAPC: −1.6 [−2.1 to −1.2]). In 2021, the global number of suicide death cases was 112.9 thousand [103.9–122.2 thousand] and led to 7.9 million [7.2–8.6 million] YLLs. A significant reduction in suicide mortality was observed in all sexes and age groups. By SDI quintiles, the high SDI region (AAPC: −0.3 [−0.6 to 0.0]) had the slowest decline trend, and low-middle SDI region remained the highest suicide mortality till 2021 (7.8 per 100,000 population [6.9–8.6]). Most SDI regions showed generally lower period and cohort effects during the study period, whereas high SDI region showed more unfavourable risks, especially period and cohort effects in females. Regionally, Central Latin America (AAPC: 1.7 [1.1–2.3]), Tropical Latin America (AAPC: 1.5 [0.9–2.0]), High-income Asia Pacific (AAPC: 1.2 [0.7–1.7]) and Southern sub-Saharan Africa (AAPC: 0.8 [0.4–1.2]) had the significance increase in suicide mortality. In 2021, Southern sub-Saharan Africa had the highest mortality (10.5 per 100,000 population [8.6–12.5]). Nationally, a total of 29 countries had a significant upward trend in suicide mortality and rate of YLLs over the past three decades, and certain countries in low-middle and middle regions exhibited an extremely higher burden of suicide.

Global suicide mortality and the rate of YLLs among adolescents and young adults both declined from 1990 to 2021, but obvious variability was observed across regions and countries. Earlier mental health education and targeted management are urgently required for adolescents and young adults in certain areas.