Smartphones, Social Media, and Adolescent Health Outcomes

Kenny Lin, MD, MPH
December 15, 2025

The negative health consequences of social media use in adolescents and young adults are increasingly being recognized. In a previous AFP Blog post on screen time use in children, Dr. Lilian White mentioned a correlation between greater social media use and reduced life satisfaction in adolescents. A 2017 Curbside Consultation discussed the relationship between social media use and mood disorders, fueled by the fear of missing out (FOMO), and reviewed resources and tools for unplugging or limiting time spent on social media.

Recently, a prospective cohort study in JAMA Network Open used objective data from a “digital phenotyping” app to evaluate the effects of a 1-week social media detox intervention on mental health. 373 U.S. young adults aged 18 to 24 years with smartphones completed a 2-week baseline assessment of their use of Facebook, Instagram, Snapchat, Tik Tok, and X. The optional intervention decreased 295 participants’ daily social media screen time from 1.9 to 0.5 hours. These changes were associated with statistically significant reduced symptoms of anxiety by 16.1%, depression by 24.8%, and insomnia by 14.5%.

Adolescents access social media platforms through smartphone apps. Another recent study examined associations of various health outcomes with smartphone ownership in a sample of more than 10,000 participants in the Adolescent Brain Cognitive Development Study. At age 12 years, 64 percent of children owned a smartphone. Compared to those without a smartphone, smartphone owners had higher risks for depression (odds ratio=1.31), obesity (OR=1.40), and insufficient sleep (OR=1.62). Risks of obesity and insufficient sleep increased with earlier age at smartphone acquisition, and the 1546 children who acquired a smartphone between the ages of 12 and 13 had worse mental health and sleep outcomes than the 1940 children who remained without smartphones at age 13.

Restricting use during school hours does not appear to affect overall smartphone or social media use or mental health. A cross-sectional study in the United Kingdom compared students at 20 secondary schools with restrictive phone policies (recreational use not permitted) with those at 10 schools with policies permitting recreational phone use. 1227 students age 12 to 15 years participated in the study, which assessed mental wellbeing using the Warwick-Edinburgh Mental Well-Being Scale. Students who attended schools with restrictive policies compensated for lower phone use during school hours by using their phones and accessing social media more after school and on weekends. Not surprisingly, there were no differences in mental well-being between the groups.

On December 10, Australia implemented the world’s first ban on social media accounts for children younger than age 16. Instagram, Facebook, Threads, Snapchat, YouTube, TikTok, Kick, Reddit, Twitch and X were all required to deactivate existing accounts for younger children and use age verification software for new accounts to avoid millions of dollars in fines. The potential health benefits of this policy remain to be seen.