COPENHAGEN, Denmark — The World Health Organization warned Wednesday of a "sharp rise in problematic social media use" among Europe's teens that it said is harming their mental health. The health body's European branch also warned that over one in 10 adolescents were at "risk of problematic gaming." Problematic use is defined as when young people present "addiction-like symptoms," the WHO Europe said. "It's clear we need immediate and sustained action to help adolescents turn the tide on potentially damaging social media use, which has been shown to lead to depression, bullying, anxiety, and poor academic performance," WHO Europe director Hans Kluge said in a statement. Addiction-like symptoms include an inability to control use, neglecting other activities in favor of social media, or seeing negative consequences in everyday life as a result of excessive use. WHO's European region comprises 53 countries and includes Central Asia. In 2022, 11 percent of adolescents (13 percent of girls and nine percent of boys) showed signs of problematic use of social networks, compared with just seven percent four years earlier, the health agency said. It cited data from 280,000 people aged 11, 13 and 15 from 44 countries in Europe, Central Asia and Canada. The phenomenon was most prevalent among female Romanian teenagers aged 13 and 15, with 28 percent affected, and least prevalent among male Dutch teenagers, where only three percent noted such symptoms. A third of adolescents play games online on a daily basis, and 22 percent of them for at least four hours, according to the WHO. Twelve percent of the entire cohort were also at risk of problematic gambling. Those most affected were young boys: 16 percent compared to seven percent of girls. "It's crucial that we take steps to protect youth to navigate the digital landscape safely and equip them to make informed choices about their online activities," Natasha Azzopardi-Muscat, Director for Country Health Policies and Systems at WHO Europe, said in a statement. At the same time, the UN agency stressed that social media also had benefits. Among young people, 36 percent — and 44 percent of 15-year-old girls — report being in constant digital contact with their friends. Young people "should rule social media, and not have social media ruling them," Azzopardi-Muscat said. WHO Europe called on national authorities to invest in embedding digital literacy in schools, enhancing mental health services, as well as training teachers and healthcare providers while enforcing accountability for social media providers.