The global burden of traumatic brain injury in adolescents and young adults, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background Traumatic brain injury (TBI) remains a leading cause of global disability among young adults, with burdens distributed unevenly across socio-demographic contexts.Methods Using Global Burden of Disease 2021 data, we analyzed TBI prevalence and years lived with disability (YLDs) for individuals aged 15–49 years across 204 countries (1990–2021). Age-standardized rates were calculated via Bayesian meta-regression (DisMod-MR 2.1), and temporal trends were assessed using the estimated annual percentage change (EAPC). Associations with the Socio-demographic Index (SDI) were examined via correlation and regression.Results Globally, prevalent TBI cases rose from 12.53 million in 1990 to 14.99 million in 2021. Conversely, age-standardized prevalence and YLD rates declined (EAPC –0.81 and –0.78, respectively). Geographically, rates increased in high-income Asia Pacific and North America but decreased elsewhere. Prevalence was consistently higher in males, peaking in the 45–49 age group. Road injuries and falls were the primary risk factors; these dominated in high-SDI regions, whereas conflict-related injuries prevailed in low-SDI settings. Age-standardized rates correlated positively with SDI (p