Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Betsy Hoza


The objective of this study was to examine the developmental trajectories of inattention and hyperactivity/impulsivity symptom levels during preschool among a majority Head Start sample of 261 three- to five-year-old children (87% Head Start; 59% Caucasian; 53% boys; Mage = 3.97 years). Teacher ratings of ADHD symptom levels across four time points within the academic year demonstrated, on average, a course of increasing inattention that decelerated over time and a course of steadily increasing hyperactivity/impulsivity. When accounting for the clustering of children within classrooms, both inattention and hyperactivity/impulsivity showed an average increasing trajectory over the year with no deceleration. Group-based finite mixture modeling revealed three trajectories of inattention: stable low (57%), change (32%), and stable high (11%), as well as three trajectories of hyperactivity/impulsivity: stable low (63%), increasing (26%), and stable high (11%). In the inattention domain, analyses that accounted for clustering within classrooms revealed a stable moderate group instead of a change group. In the hyperactivity/impulsivity domain, findings held even when accounting for clustering. Group-based comparisons showed that as compared to girls, boys started the preschool year with higher levels of inattention and hyperactivity/impulsivity symptoms, had greater rates of increase in these symptoms over time, and were more likely to follow a high stable or increasing pattern of these symptoms over the year. Being younger was associated with higher inattention levels at the start of the preschool year but the rate of change in inattention was not associated with age. Children with stable high inattention were more likely to be younger than children with stable low inattention. Age was not associated with hyperactivity/impulsivity at the start of the preschool year but being older was linked with a steeper increase in these symptom levels over the course of the year. There were no differences in the mean age of children following different pathways of hyperactivity/impulsivity symptom levels through the year. Implications for assessment and intervention of ADHD during preschool are discussed.



Number of Pages

81 p.

Available for download on Sunday, May 29, 2022