The Cross‐Sectional and Longitudinal Associations Between Social Media and Mental Health Among a Large Sample of Adolescents, Inclusive of Transgender/Gender‐Diverse Adolescents

INTRODUCTION: The objectives of this study were to examine: (1) the cross-sectional and longitudinal associations between social media (SM) time and mental health outcomes among a large sample of Canadian adolescents (ages 12-18) and (2) if associations are moderated by gender. METHODS: Data from the Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking, and Sedentary behaviour (COMPASS) study were used to conduct two cross-sectional analyses (2021/2022: n = 58,289; 2022/2023: n = 44,777) and a linked longitudinal analysis (2021/2022 to 2022/2023: n = 26,743). The exposure variable was time spent browsing/scrolling SM (cross-sectionally), and the change in SM time from baseline to follow-up (longitudinally). The outcome variables were anxiety, depression, flourishing, personal relationships, and emotional regulation (measured at follow-up in longitudinal models). The moderator variable was gender, categorized into cisgender girls, cisgender boys, and transgender/gender-diverse adolescents. Multilevel linear modeling was conducted. RESULTS: An additional hour/day of SM (cross-sectionally) and one additional hour/day of SM from baseline to follow-up (longitudinally) was significantly associated with increased depression and anxiety symptoms, decreased flourishing, and poorer personal relationships and emotional regulation at follow-up. Gender was a significant moderator of SM time and mental health outcome associations cross-sectionally, but gender did not moderate change in SM time and mental health outcome associations longitudinally. Cisgender girls experienced significantly larger negative associations between SM time and mental health outcomes in comparison to cisgender boys and transgender/gender-diverse adolescents cross-sectionally. CONCLUSIONS: Among Canadian adolescents, SM time was associated with poorer mental health outcomes both cross-sectionally and over 1 year.