The world loses about 3,000 adolescents each day. That adds up to 1.2 million deaths a year. And with a bit more investment, the majority of those deaths can be prevented, according to a global study released on Tuesday by the World Health Organization.That's far fewer than the 16,000 babies and children under 5 who die each day. But the WHO report points out that while many programs around the world are dedicated to improving infant mortality, very few programs address for the needs of vulnerable tweens and teens.We interviewed WHO epidemiologist Kate Strong — one of the study authors — to learn more about those needs, and what it will take to meet them.The interview has been edited for length and clarity.Tell us why WHO has released this report now?Adolescent health has really been overlooked. We've had a big focus on newborn and child health, but it's only within the last decade that we've begun to focus on this particular age group.Maybe it's not a conscious thought, but the thought [in the global health world] was once you make it past five, you're pretty much going to have a healthy and long life.Adolescence is actually a time period when a lot of physiological and mental changes happen, and many of these changes make adolescents particularly vulnerable.Teen girls in many parts of the world, for example, are especially vulnerable to complications during pregnancy because their bodies are still developing.Adolescents also seem especially vulnerable to mental health issues compared to other age groups. Self-harm is a leading cause of death. And the report also found that this age group has high rates of depression and anxiety disorders. Shifting hormones, as well as adolescents' shifting roles and responsibilities in society, can cause a lot of stress, strain and anxiety.That's why the more information we have about mental health for adolescents, parents and teachers, the better. They need to know that help is available and where they can get that help.There have been a lot of countries that have made very specific interventions in terms of adolescent mental health that we've included as case studies in the report.The Islamic Republic of Iran's school mental health promotion project is aimed at improving students' self-esteem and reducing fear of exams. That program started on a small level in one community and was scaled up to a national level.New Zealand has also taken steps with a program to reduce suicide among Maori youth.Can you break down some of the stats in this report for us? For example, I was surprised to learn that drowning was a leading issue among adolescent boys. While I can't comment on the specifics of why certain illnesses and injuries affect certain groups more, the report does suggest that in many communities kids just aren't taught how to swim. And that can be easily fixed.Were you surprised by any of the figures in this report?I will say, I was really struck by the rates of HIV and infectious diseases, which account for about a quarter of adolescent deaths in Africa. The same goes for pneumonia, a leading cause of death for younger adolescent girls in that region. These deaths are entirely preventable.To encourage young teens to think about risks to their health, WHO created a comic book starring two youngsters called Akilah and Carlos and their imaginary friend (a parrot called Miss P). They help their friend hurts himself while climbing a tree, get to the local health clinic. And they help a classmate who's depressed find a counselor. And you consulted with kids about the comic book. Why?With adults when we do interventions we always ask them what they think and what they would be comfortable with.We need to have those same conversations with adolescents. They can be and they should be part of the solution.Maanvi Singh is a freelance writer based in London. Contact her @maanvisings Copyright 2017 NPR. To see more, visit http://www.npr.org/.