Screen Time and Puberty Timing: Findings from the Adolescent Brain Cognitive Development Study

ObjectiveTo examine whether screen time predicts interindividual variability regarding pubertal development across adolescence. Study designThis longitudinal cohort study included 10786 participants (47.9% female) from the Adolescent Brain Cognitive Development (ABCD) study. First, associations were examined between average daily screen time (hours/day, parent-reported Screen Time Survey) at baseline (mean age = 9.91 {+/-} 0.63 years) and pubertal timing, derived from Pubertal Development Scale (PDS) scores through 4-year follow-up (mean age = 14.08 {+/-} 0.68 years) and standardized by age and sex. Second, associations were examined between screen time groups (very low: 0-1.29 h/day; low: 1.29-2.07 h/day; moderate: 2.07-2.86 h/day; high: 2.86-4.0 h/day; very high: 4.00-12.43 h/day) and age at mid-puberty, defined as the age at first parent report of Pubertal Development Scale (PDS) category at least 3. ResultsIn linear mixed models adjusting for age, sex, race/ethnicity, socioeconomic status, BMI, and physical activity, higher log-transformed screen time at baseline was associated with more advanced pubertal timing at 1-, 2- and 3- year follow-ups, with the strongest effect observed at year 2 (standardized {beta}=0.07 [95%-CI, 0.05 to 0.10]). The associations were more pronounced in girls. The group of participants with very high screen time reached mid-puberty 2.47 months earlier [adjusted effect size, 95%-CI, -3.38 to -1.56) than participants with very low screen time. ConclusionThese findings suggest that screen time in late childhood is linked with earlier pubertal development and highlight its relevance for parental guidance on preadolescents screen media use.