Informants’ ratings of activity level in infancy predict ADHD symptoms and diagnoses in childhood

We tested the hypothesis that high activity levels in infancy would predict self-regulatory problems and later symptoms of attention deficit and hyperactivity disorder (ADHD) in a longitudinal study of British families ( N = 321). Infants’ activity levels were assessed at 6 months, using 3 informants’ reports from the Infant Behavior Questionnaire (IBQ) and ActiGraphs during baseline, attention, and restraint tasks. At a mean of 33 months, the...