ADHD News & Research

Study: Inattention Decreases, Hyperactivity Increases in Most Preschool Students with ADHD

Symptoms of inattention decelerate in a third of preschool students with ADHD, while hyperactive and impulsive symptoms steadily increase during the school year for a quarter, according to a new study examining the developmental course of teacher-rated ADHD symptoms across one academic preschool year.

March 17, 2021

One-quarter to one-third of preschool students with ADHD demonstrated decelerating inattention and increasing hyperactivity over the course of an academic school year, according to a new Journal of Attention Disorders study1 — one of the first studies of the developmental course of ADHD to incorporate teacher ratings and not rely exclusively on parent reports. Because an ADHD diagnosis requires the presence of impairing symptoms in multiple settings, charting and assessing the teacher perspective is a critical component to improving assessment in young children.

In this new study, teachers rated the ADHD symptom levels of 261 preschool children four times throughout the academic school year. Findings suggested that nearly a third of students’ inattention increased and then decelerated over time, while 26% of students saw hyperactivity and impulsivity steadily increase. Researchers noted three trajectories of inattention — stable low (57%), change (32%), and stable high (11%) — and three trajectories of hyperactivity/impulsivity — stable low (63%), increasing (26%), and stable high (11%). Children with stable high symptom levels were more impaired than were children with stable low symptom levels.

These results may help teachers better identify early signs of ADHD. Researchers concluded that, even though health care providers and educators might adopt a “wait and see” approach to avoid over-pathologizing normal behaviors, “results from the current study suggest that, on average, symptom elevations either remain stable or increase over the course of the year. Though certainly in need of replication, our findings suggest that we should not dismiss elevated ADHD symptoms in early childhood as transient or time limited.”


1 Martin CP, Shoulberg EK, Hoza B. The Developmental Course of Teacher-Rated ADHD Symptom Levels in an Early Childhood Community Sample. Journal of Attention Disorders. March 2021. doi:10.1177/1087054721997561