New Zealand's male adolescent suicide rate is the worst and its adolescent death rate the second worst among 27 high-income countries, according to new research.
The study published in The Lancet analysed international health indicators from 72 countries and included a sub-analysis of 27 high-income countries.
It finds that the United States has the highest mortality rates among people aged 10-24 among the 27 high-income countries, due to its high rate of deaths from violence and road accidents.
New Zealand adolescents had the second highest overall mortality. NZ males and females ranked 27th and 22nd respectively for suicide, and 24th and 26th for traffic deaths.
Kiwi adolescents' deaths from violence ranked 11th of the 27 countries.
Professor David Fergusson, from Otago University's department of psychological medicine, says the reasons for New Zealand's relatively high youth mortality are not fully understood.
"These rates are largely a reflection of two factors that contribute to mortality in young people: motor vehicle accidents and suicide," he said.
"New Zealand's high rates of MVAs may to some extent reflect the age (15) at which young New Zealanders begin to drive giving them greater exposure to risk than young people in other societies where the legal driving age is older."
Prof Fergusson said the reasons for the higher youth suicide rates are largely unknown.
But some of the countries with high youth suicide rates, including New Zealand, Finland and Ireland, are small liberal democracies with high rates of alcohol consumption.
The Lancet says the 1.8 billion adolescents in the world today are more exposed to harmful alcohol consumption, sexually transmitted diseases, and other risks than in the past, and face other new challenges such as social media.