Social Media Use and Mental Health among Racially/Ethnically Minoritized Adolescents - PROJECT SUMMARY Mental health problems among U.S. adolescents have risen precipitously in the past decade, along with social media use, now a staple of adolescent communication and social interaction. Though many believe this is not coincidence, evidence linking the two are mixed at best. A deeper understanding of the developmental connections between social media use and mental health has been severely hindered by a distinct dearth of longitudinal data, scant examination of the dynamic interplay of social media use and mental health among racially/ethnically minoritized youth, and a puzzling omission of the mental health implications of social media content. To fill this critical gap, a longitudinal mixed-methods study is proposed with 250 racially/ethnically minoritized youth and their primary caregivers. In Phase 1, preliminary data will be collected from 50 adolescents and their primary caregivers to optimize research procedures. In Phase 2, a full-scale longitudinal data collection will be completed with 200 adolescents and their primary caregivers. Data collection in both Phases will focus on intensive 9-day-long periods where the research team will (1) use Ecological Momentary Assessment (EMA) four times per day to measure adolescents’ social media use and mental health in natural settings and (2) continuously capture screenshots of adolescents’ phone screens every 5 seconds to measure an individual’s social media content exposure. These “EMA/Screenshots epochs” will be supplemented with (1) detailed surveys of adolescent social media use, mental health, and other relevant factors from youth-caregiver dyads and (2) interviews with youth. Phase 1 will only involve 1 EMA/Screenshots epoch and a single follow-up survey/interview. Phase 2 will involve 9 EMA/Screenshots epochs (3 years x 3 epochs/year in fall, spring, and summer) and 3 annual surveys/interviews. The Phase 2 design will enable the examination of the bidirectional dynamics between social media use and mental health on daily (Aim 2) and day-to-year (Aim 3) timescales. This highly innovative project will provide urgently needed information regarding the development of youth social media use and mental health across middle to high school ages, their reciprocal influences in both the daily and yearly timescales, and mechanisms of risk for, and resilience against adverse outcomes. This work will provide critical insights and information needed to inform interventions aimed at mitigating the negative impact and maximizing the benefit of social media use for racially/ethnically minoritized adolescents’ mental health.