Between 2010 and 2015, adolescent mental health took a marked downturn in many countries. Rates of anxiety, depression, self-harm, and suicide saw a significant rise, particularly among teenage girls. This timeframe coincided with a notable shift from a play-based childhood to a phone-based one. Prior to 2010, most teens did not own smartphones, and they primarily engaged in face-to-face social activities. The advent of smartphones provided constant access to social media, video games, and online content, fundamentally altering teen culture.

Studies consistently show a surge in mental illness among teens post-2010, with sharp increases in self-reported anxiety and depression. Teens increasingly visited emergency rooms for self-harm and suicide attempts. This pattern was observed similarly across English-speaking countries like the U.S., Canada, and the U.K. Global surveys also noted a rise in teen loneliness after 2012.

Preteen and young teen girls experienced the most severe decline. Emergency room visits due to self-harm nearly tripled for this group between 2010 and 2020, and suicide rates for girls aged 10 to 14 rose significantly starting around 2008. This widespread decline in mental health cannot be attributed to any single event, including COVID-19, school shootings, or climate change concerns. The most plausible cause is the rapid adoption of smartphones with social media, reshaping how teens socialize and perceive themselves.

Overall, the move to a phone-based childhood has led to increased anxiety, depression, and disconnection from real-world relationships among teens. Reversing these trends will necessitate a return to play, meaningful friendships, and the strengthening of family bonds.