- New global figures reveal most common causes of death and ill health for 10-24 year olds
- "Young people are the world's greatest untapped resource", writes UN Secretary-General Ban Ki-moon
- For key Global Burden of Disease (GBD) findings see end of release
Decades of neglect and chronic underinvestment have had serious detrimental effects on the health and wellbeing of adolescents aged 10-24 years, according to a major new Lancet Commission on adolescent health and wellbeing being launched in London on Tuesday, May 10, 2016 . Two-thirds of young people are growing up in countries where preventable and treatable health problems like HIV/AIDS, early pregnancy, unsafe sex, depression, injury, and violence remain a daily threat to their health, wellbeing, and life chances.
Evidence shows that behaviours that start in adolescence can determine health and wellbeing for a lifetime. Adolescents today also face new challenges, including rising levels of obesity and mental health disorders, high unemployment, and the risk of radicalisation.
Adolescent health and wellbeing is also a key driver of a wide range of the Sustainable Development Goals  on health, nutrition, education, gender, equality and food security, and the costs of inaction are enormous, warn the authors.
The Commission's findings should be a wake-up call for major new investment in the largest generation of adolescents in the world's history (1.8 billion) that will yield a triple dividend of benefits -- today, into adulthood, and for the next generation of children.
"This generation of young people can transform all our futures. There is no more pressing task in global health than ensuring they have the resources to do so. This means it will be crucial to invest urgently in their health, education, livelihoods, and participation," says the Commission's lead author Professor George Patton, University of Melbourne, Australia. 
The Commission brings together 30 of the world's leading experts from 14 countries and two young health advocates, led by four academic institutions: the University of Melbourne, Australia; University College London, UK; the London School of Hygiene & Tropical Medicine, UK; and Columbia University Mailman School of Public Health, USA.
Adolescents aged 10-24 years represent over a quarter of the population (1.8 billion), 89% of whom live in developing countries. Their number is set to rise to about 2 billion by 2032. Adolescence is a critical time of formative growth and brain development second only to infancy (Commission, panel 3). "Puberty triggers a cascading process of brain development and emotional change that continues through to the mid-20s. It brings a different and more intense engagement with the world beyond an adolescent's immediate family. These processes shape an individual's identity and the capabilities he/she takes forward into later life. It profoundly shapes health and wellbeing across the life-course,"  explains Professor Patton.
Most health problems and lifestyle risk factors for disease in later life also emerge during these years (eg, mental health disorders, obesity, smoking, unsafe sex). But because adolescence is generally thought to be the healthiest time of life, young people have attracted little interest and too few resources. Indeed, adolescents aged 10-24 years have the poorest health-care coverage of any age group.
Although global health efforts have been successful in improving the health of children under 5 in the past few decades, this has not been matched by a similar response in older age groups. Although global mortality has fallen for young people aged 10-24 years since 1990, the pace of decline has been slower than in younger children, especially for males, according to a major new international analysis of findings from the Global Burden of Disease (GBD) project led by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington, Seattle, USA , published alongside the Commission (GBD appendix, figure 2 page 5).
The IHME analysis reveals that HIV/AIDS, road traffic accidents, and drowning caused a quarter of deaths in 10-14 year olds globally in 2013, with diarrhoeal and intestinal infectious diseases, lower respiratory infections, and malaria contributing to a further 21% of deaths. Road traffic accidents (14.2% and 15.6%), self-harm (8.4% and 9.3%), and violence (5.5% and 6.6%) were the leading causes of death for 15-19 year olds and 20-24 years olds respectively.
Depression resulted in the largest amount of ill health worldwide in 2013, affecting more than 10% of 10-24 year olds , followed by the rising burden of skin and subcutaneous diseases (9.9%) like acne and dermatitis (GBD appendix, table 3).
The fastest-growing risk factor for ill health in young people aged 10-24 years over the past 23 years is unsafe sex (GDB appendix, figure 4). Alcohol remains the world's leading risk factor for ill health in young adults aged 20-24 responsible for 7% of the disease burden, followed by drug use accounting for 2.7% (GBD paper, figure 7).
"Our data show a clear need for renewed efforts to improve health and reduce the burden of disease in young people. Continued inaction will have serious ramifications for the health of this generation and the next," warns lead author Ali Mokdad, Professor of Global Health at IHME. "Most of these health problems are preventable and treatable and tackling them will also bring huge social and economic benefits. The vast disparities between countries in risk and burden of disease mean that different interventions will be needed to address each country's unique needs. Future work needs to examine the effect and cost-effectiveness of such interventions."
The Commission finds that some of the most effective actions to improve adolescent health and wellbeing lie in sectors beyond health services (Commission, table 6) "The single best investment we can make is guaranteeing access to free, quality secondary education," explains Professor Patton. "Every year of education beyond age 12 is associated with fewer births for adolescent girls and fewer adolescent deaths for boys and girls. A healthy, educated workforce has the potential to shape a country's economic prospects."
It is crucial to involve young people in transforming their wellbeing, personal development, and health, say the authors. Digital media and new technologies offer remarkable opportunities to engage and empower young people to drive change. There is also a pressing need to ensure that all young people have opportunities and access to universal health coverage regardless of age, gender, sexual orientation, and marital, and socioeconomic status, particularly the marginalised.
"Young people are the world's greatest untapped resource," says UN Secretary-General Ban Ki-moon writing in a linked Comment. "Adolescents can be key driving forces in building a future of dignity for all. If we can make a positive difference in the lives of 10-year-old girls and boys today, and expand their opportunities and capabilities over the next 15 years, we can ensure the success of the SDGs. For me, the acronym "SDG" also stands for "Sustainable Development Generation", and sustainability means engaging future generations today."
The Commission authors make several recommendations to improve prospects for adolescent health and wellbeing echoing those of The Global Strategy for Women's, Children's, and Adolescents' Health launched in September, 2015 --leading with the urgent need to expand access to free secondary education; get serious about the laws that empower and protect adolescents such as guaranteeing 18 years as the minimum age for marriage; and continue gathering better evidence for action particularly around mental health and violence. Other recommendations include collecting and reporting on a minimum set of priority indicators for adolescent health reflecting the burden of disease and risk factors, and for robust, transparent governance and accountability for adolescent health.
Because adolescent health varies between and within countries, different interventions will be needed to address each country's unique needs. The Commission therefore groups countries into three categories (Commission, panel 7 & figure 8) -- multi-burden countries, injury excess, and non-communicable diseases -- to help donors and national governments assess the best package of interventions.
Melinda Gates from The Bill & Melinda Gates Foundation adds, "My children's generation is better equipped to expand the limits of human possibility than any that has gone before. But while responsibility for their health and wellbeing lies with everyone, accountability currently rests with no one. Bill and I are personally committed to advancing the adolescent health agenda through the work of our foundation, in partnership with governments and the international community. For too long adolescents have been the forgotten community of the health and development agenda. We cannot afford to neglect them any longer." 
Key global findings from GBD paper [country data available on request -- see below]:
- While global efforts to improve the health of children under 5 have led to major improvements in younger ages, the leading causes of death for young people aged 10-24 years have changed remarkably little from 1990 to 2013, with road injuries, self-harm, violence, and tuberculosis remaining in the top five (table 1 and appendix page 1).
- Maternal disorders were the leading cause of death in young women in 2013, responsible for 17% of deaths in women aged 20-24 years and 11.5% in girls aged 15-19 years.
- The leading risk factors for death in young people aged 10-14 years have not changed in the past 23 years, with unsafe water, unsafe sanitation, and handwashing remaining in the top three. Diarrheal and intestinal diseases are still responsible for 12% of deaths in 10-14 year old girls.
- Injuries, mental health conditions, common infectious diseases, and sexual and reproductive health problems are the dominant health problems in young people.
- In both males (18.8%) and females (15.6%) aged 10-14 years, iron deficiency is the leading cause of ill health (years lived with disability (YLD)--ie, time spent in less than optimum health), whereas depressive disorders are the leading cause of ill health for females aged 15-19 years and 20-24 years (table 2 appendix page 2).
- The two main contributors to health loss worldwide for both sexes are mental health disorders and road injuries (measured in terms of disability adjusted life years (DALYS)--the proportion of lost years of healthy life due to illness rather than death).
- These causes of health loss differed by gender: for males, road injuries were ranked among the top-four contributors to all age groups, while females lose substantially more health to iron deficiency and depression than their male counterparts (figures 5-7).
- Unsafe sex has become a key risk factor for health loss (DALYs) in both males and females aged 15-19 years old, rising from 13th place in 1990 to 2nd place in 2013 (figure 3).
NOTES TO EDITORS:
Both the Commission and GBD study were funded by the Bill & Melinda Gates Foundation.
 Background about the Commission, including full list of Commissioners available at: http://thelancetyouth.
 The Sustainable Development Goals (SDGs) are designed to guide national and international actions for the next 15 years related to health, nutrition, education, gender, equality, and food security. https:/
 Quotes direct from authors and cannot be found in text of Commission, Article or Comments.
 The authors used data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2013 to quantify levels, patterns, and trends in ill health, disability, and death in young people in 188 countries between 1990 and 2013 to reveal the substantial toll of disabling disorders and the overall burden on health systems from 306 diseases and injuries, as well as 1233 health consequences (sequelae) that result from these disorders, and 79 risk factors. The Global Burden of Disease project is an international collaboration involving more than 1,500 researchers in more than 110 countries, coordinated by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington.
 Measured in terms of YLD--years lived with disability--ie, time spent in less than optimum health.