Infant attention and frontal EEG neuromarkers of childhood ADHD.

Numerous electroencephalogram (EEG) studies have sought to elucidate the neural mechanisms of attention deficit hyperactivity disorder (ADHD), with most of the existing literature focused on children, adolescents, and adults. In this retrospective study, measures of frontal EEG power and behavioral attention of 40 5-month-old infants later diagnosed with ADHD in childhood were compared to 40 systematically matched-control infants. Compared to the control group, infants in the ADHD group exhibited longer looking fixations during an attention task. Frontal EEG power in the 6-9 Hz infant alpha band was lower in the ADHD group compared to the control group. Mean frontal EEG power was associated with visual fixations, underscoring specific attention behavior corresponding to frontal brain development in infancy. Infants later diagnosed with ADHD exhibited higher attention problems in childhood at ages 4 and 9 compared to the control group, and longer looking fixations in infancy were associated with higher childhood ADHD-related symptomatology. These findings suggest that decreased infant frontal EEG power and looking fixations as early as 5-months of age may serve as important early markers of later ADHD and can aid in building a more comprehensive model of ADHD from a developmental neuroscience approach.