Prospective associations of screen time at age 2 with specific behavioral subscales at age 3: a cohort study

Background We aim to discover which, if any, of the subscales of internalizing and externalizing behavioral problems at age 3 are still associated with screen time (ST) at age 2 after adjusting for behavioral problems scores at age 2. Methods This study was conducted under the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Information was gathered prospectively, with 7207 mother–child pairs included in the analysis. Children’s ST was categorized in hours a day at age 2 (<1, 1-<2, 2-<4, ≥4). We assessed children’s behavioral problems using the Child Behavior Checklist for Ages 1½–5 (CBCL) at ages 2 and 3. ‘Having behavioral problems’ was defined by them being within a clinical range for internalizing behaviors (withdrawn, somatic complaints, anxious/depressed and emotionally reactive) and externalizing behaviors (attention problems and aggressive behaviors) at age 3. Continuous scores on each of the behavioral problem scales at age 2 were used as covariates. Results Greater ST for children at age 2 was associated with specific subscales for emotionally reactive and aggressive behaviors at age 3. Conclusions This study found that ST is prospectively associated with some behavioral scales but not others.