Social Media Detox and Youth Mental Health.

Importance: The association between social media use and youth mental health remains poorly understood, with recent systematic reviews reporting inconsistent and conflicting findings. These discrepancies reflect the overreliance on self-reported estimates of use, lack of passive monitoring of behavior, and limited measurement of momentary mental health states. Objectives: To examine the association between objective social media use, problematic engagement, and mental health outcomes in young adults, as well as evaluate the outcomes of a 1-week social media detox intervention on behavior and mental health symptoms. Design, Setting, and Participants: A remote cohort study conducted in the US using a national recruitment registry between March 2024 and March 2025, where participants completed a 2-week observational baseline, followed by an optional 1-week social media detox intervention. Participants were young adults (aged 18-24 years) with a smartphone and English fluency. Exposures: Social media use of Facebook, Instagram, Snapchat, TikTok, and X over a 2-week baseline period, followed by an optional 1-week detox intervention. Main Outcomes and Measures: The main outcomes were detox changes in symptoms of depression (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder-7), insomnia (Insomnia Severity Index), and loneliness (University of California, Los Angeles Loneliness Scale), as well as within-participant changes in behavior including screen use, communication, mobility, and momentary mental health states. Results: Of 417 enrolled participants, 373 (mean [SD] age, 21.0 [1.9] years) completed baseline assessments, with 295 (79.1%) opting into a detox intervention that reduced symptoms anxiety by 16.1% (-1.9 reduction; Cohen d, -0.44; 95% CI, -0.56 to -0.32), depression by 24.8% (-2.0 reduction; Cohen d, -0.37; 95% CI, -0.49 to -0.32) and insomnia by 14.5% (-2.1 reduction; Cohen d, -0.44; 95% CI, -0.56 to -0.32). There was no significant change in loneliness (Cohen d, -0.40; 95% CI, -0.17 to 0.06). Marginal increases were seen in home time (β, 42.8; 95% CI, 24.3 to 61.2 minutes) and screen duration (β, 15.4; 95% CI, 4.9 to 25.9 seconds), with considerable within-person variability. No other changes in behavioral or EMA-based features were observed after the detox. Conclusions and Relevance: In this cohort of young adults, reducing social media use for 1 week was associated with reductions in symptoms of depression, anxiety, and insomnia; however, the durability of these therapeutic outcomes and their associations with behavior warrant further study, particularly in more diverse populations.