No matter where in the world teens live, depression is their main cause of illness and disability, finds a new report from the World Health Organization that seeks to shine more attention on the health issues of youth.

The report, called "Health for the world’s adolescents," finds depression is the No. 1 cause of illness among teens, and suicide is the No. 3 cause of death. Only road accidents and HIV/ AIDS cause more teen deaths than suicide.

The report found that since half of all people who develop mental disorders report experiencing their first symptoms by age 14, getting teens the mental health care they need could prevent thousands of deaths as well as suffering.

Overall, the top 3 causes of the 1.3 million teen deaths every year are road accidents, followed by HIV/AIDS, and suicide.

Road accidents are also the No. 2 cause of illness and disability, with boys disproportionately affected, with their death rate from accidents three times the rate of girls.

The WHO report authors say increasing access to reliable and safe public transport could help reduce these injuries and deaths. Other measures that could help include:

  • speed limits
  • alcohol regulation
  • safe pedestrian areas around schools
  • graduated drivers' licensing schemes

Also contained in the report is the finding that deaths due to complications of pregnancy and childbirth have dropped significantly among teen girls since 2000. Southeast Asia and the eastern Mediterranean region have seen estimated death declines of 57 and 50 per cent respectively.

"Despite these improvements, maternal mortality still ranks second among causes of death among 15 to 19-year-old girls globally, exceeded only by suicide," the report authors say.

But the number of teen deaths related to HIV is rising – mainly in the African region -- at a time when HIV-related deaths are decreasing in all other population groups.

The report also took a look at which countries have created health policies specifically for teens. It pointed to India, which just created a new teen health strategy that addresses several health issues, including substance use, violence, mental health, and non-communicable diseases, in addition to sexual and reproductive health.

The report found of the 109 countries it reviewed, 84 per cent give some attention to adolescents – generally in the area of sexual and reproductive health. But only one-third addressed teens' tobacco and alcohol use, and only one-quarter addressed mental health.