HELSINKI — Heavy social media use is undermining youth well-being in many countries, according to a United Nations-sponsored report published on Thursday.

This year's World Happiness Report highlighted the impact of social media as many countries impose or mull legislative restrictions on social media use for young people.

"Dramatic declines" in happiness were recorded among under 25s in the United States, Canada, Australia and New Zealand, and "especially among girls", the report said.

By contrast, young people in other parts of the world felt better about their lives.

"Most of the world's young people are happier today than they were 20 years ago, and that's a trend that deserves attention," Jon Clifton, chief executive of Gallup, which contributed to the report, said in a statement.

Social media has a "complex" effect on well-being, the report noted.

Impacting factors include time spent on social media sites, the type of platform, how it was used, as well as demographic factors such as gender and socioeconomic status.

"Heavy usage is associated with much lower well-being, but those deliberately off social media also appear to be missing out on some positive effects," said Jan-Emmanuel De Neve, one of the report's editors and an economics professor at Oxford University and director of its Wellbeing Research Centre.

Happiness index

Based on a three-year average, the happiness index considers six factors: GDP per capita, life expectancy, social support, freedom to make life choices, generosity, and perceptions of corruption.

Among 147 countries listed, the lowest levels of life satisfaction were reported from conflict-torn Afghanistan.

Nordic nations continue to dominate the rankings, with Finland, Iceland, Denmark, Sweden and Norway taking five of the top six spots this year.

Costa Rica was ranked fourth, entering the top five for the first time and the highest ranking ever for a Latin American country.

Agencies via Xinhua