Temperament and executive functioning correlates of ADHD symptom severity during early versus middle childhood.

Background: This study investigated associations among temperament, executive functioning (EF), and attention-deficit/hyperactivity disorder (ADHD) symptom severity at two developmental stages.

Methods: Participants were 61 4-year-old children and 165 8-11-year-old children (126 ADHD, 39 typically developing [TD]). Caregivers reported on temperament (effortful control [EC], negative affect, and surgency), and ADHD symptoms.

EEG aperiodic dynamics from early through late childhood: Associations with ADHD, cognition, and development.

Background: Aperiodic resting electroencephalography (EEG) activity is dynamic, reflecting shifting excitatory:inhibitory (E:I) balance with changing environmental conditions. We examined developmental and cognitive correlates of aperiodic and dynamic aperiodic indices in a cross-sequential cohort of early, middle, and late childhood youth with and without attention deficit hyperactivity disorder (ADHD).

Methods: Two-hundred eighty-five children ages 2 - 14 years provided resting EEG during high- and low-visual input conditions.