External causes of mortality are among the leading causes of mortality, especially in low- and middle-income countries. External causes of mortality disproportionately affect youth and young adults, including those who are economically active. The aim of the following study series was to investigate trends and demographic associations of the injury-related mortality burden and suicidal behavior in low- and middle-income countries.

Study I examined trends of external causes of mortality in Seychelles over a period of 30 years using civil registration data. At least three-quarters of injury deaths occurred among males. The leading causes of mortality among males was drowning, followed by road traffic injuries; and other unintentional injuries among females. The injury mortality declined over time; however, the injuries from road traffic crashes increased, especially among males.

Study II analyzed trends of traumatic brain injury (TBI) related mortality in Seychelles over a span of 30 years using civil registration data. Males were more likely to die from TBI related injuries. TBIs contributed to one in five deaths from all the recorded external causes. Road traffic crashes were the leading mechanism of TBI related mortality.

Study III estimated the prevalence of suicidal behavior and the associated contextual factors among adolescents in low- and middle-income countries using the Global School-based Student Health Survey data. Ten to eleven percent of adolescents had considered suicide, made a suicide plan, or attempted suicide in each case. The lowest prevalence was reported in the South East Asian region, while a higher prevalence was recorded in the low-income country regions of the Americas.

The findings imply that effective policies tailored for low- and middle-income countries are required to reduce the high rates of injury mortality. Reducing injury mortality will contribute towards each respective economy by minimizing the losses of income faced by the economically active age groups, which will in turn be beneficial for the countries.