Over the past few decades and throughout the world, the landscape of adolescent health has been altered dramatically. Currently, the total population of adolescents between the ages of 10 and 19 years is 1.2 billion – the largest generation of young people in history. The vast majority of adolescents (85%) live in developing countries where, in many areas, they make up more than a third of the population. They face a variety of different experiences given the diverse political, economic, social and cultural realities within their communities. Although, for many, adolescence is a period of learning and building confidence in a nurturing environment, for others it is a period of heightened risk and complex challenges.