The Effects of Social Media on Adolescent Mental Health: Findings From a Population‐Based Cohort Study in Australia

OBJECTIVES: To examine the effects of social media on future mental health problems (depressive symptoms, anxiety symptoms, poor well-being and self-harm) in adolescents aged 12-18 years, overall and stratified by sex and age periods (early, middle and late adolescence). STUDY TYPE: Prospective longitudinal study. SETTING: Participants were recruited in 2012 through schools in Melbourne, selected using stratified random sampling. In wave 1 (2012), 1239 Grade 3 students participated and have since completed annual surveys. PARTICIPANTS: The analysis used data up to wave 11 (2022). Participants with no data on mental health, social media and confounders were excluded, leaving a sample of 1195 (552 [46%] male participants). MAIN OUTCOME MEASURES: Exposure was self-reported duration of daily social media use at each wave, from waves 4 to 10 (ages 12-18 years). Outcomes (self-reported depressive symptoms, anxiety symptoms, well-being, self-harm) were assessed at the subsequent annual wave, from waves 5 to 11 (ages 13-19 years). RESULTS: Across adolescence, > 2 h versus < 1 h of daily social media use was associated with a small increase in risk of high depressive symptoms (risk difference [RD] per 100, 6.3 [95% CI, 2.7-9.9]) and poor well-being (RD, 4.9 [95% CI, 1.1-8.6]) at the subsequent annual wave. Estimated risks for all mental health problems were greatest in early adolescence (12-13 years), with the largest effects observed for high depressive symptoms in female participants (> 2 h vs. < 1 h: RD, 10.8 [95% CI, 2.7-18.9]). CONCLUSIONS: Higher levels of social media use were associated with small increases in future risk of high depressive symptoms and poor well-being across adolescence. The largest risks for all mental health problems were observed during early adolescence for both male and female participants, supporting the need to consider policies that mitigate the adverse effects of social media on the mental health of younger adolescents.