Young people are a nation’s greatest asset for growth, prosperity, innovation, and current and future workforce and social support: it makes sense to invest in their health. The 21st century heralds the largest global population of young people ever previously known with a total of 1.8 billion individuals aged 10–24 years, 90% of whom live in low-income countries.1 Young people represent more than one-third of the population in low-income countries, and one-sixth to one-fifth of the population in high-income countries such as the UK. Yet, until recently the health needs of young people have been poorly understood and marginalised. The first WHO/UNFPA/UNICEF report on programming for adolescent health and development was issued less than 20 years ago.1
The need for a global focus on young people’s health is evidenced by a landmark study of 50-year global mortality trends showing that mortality in young people aged 15–24 years is now higher than in children aged 1–4 years, with mortality of young males in this age group, two- to threefold higher than in the first decade of life.2 Furthermore, the major causes of morbidity and mortality in adolescence are largely preventable such as transport injuries, violence, suicide, rising rates of mental health issues, substance abuse, sexually transmitted infections including HIV, and precancerous lesions. Prevention and early intervention have thus dominated the recommended healthcare responses to these health risks.
The World Health Organization definition of adolescence refers to young people between the ages of 10 and 19 years. However, in this article we define adolescence to be synonymous with young people, encompassing the ages of 10–24 years, because the biological, psychological, and social role transitions of adolescence affect the health of young people throughout this age range. Many of the risk factors for disease in adulthood begin in adolescence; for …