Moderate-to-vigorous physical activity and processing speed: predicting adaptive change in ADHD levels and related impairments in preschoolers

Abstract

Background: Preschool ADHD symptoms have predictive utility for later presence of ADHD diagnoses (Harvey, Youngwirth, Thakar, & Errazuriz, 2009, Journal of Consulting and Clinical Psychology, 77, 349; Lahey et al., 2004, American Journal of Psychiatry, 161(11), 2014), yet some level of inattention, hyperactivity, and impulsivity are present even in typically developing preschoolers. Physical activity (PA) is known to have a broad spectrum of positive effects on the brain in school-age typically developing children (Centers for Disease Control and Prevention, 2010, The association between school based physical activity, including physical education, and academic performance. Atlanta, GA: U.S. Department of Health and Human Services), including functions impaired by ADHD (Halperin, Berwid, & O'Neill, 2014, Child and Adolescent Psychiatric Clinics of North America, 23, 899), yet links between PA and ADHD levels and impairments have rarely been studied in either typically developing or at-risk preschool children. Importantly, impaired processing speed (PS), though not a symptom of ADHD, is a robust neuropsychological correlate (Willcutt & Bidwell, 2011, Treating attention deficit hyperactivity disorder: Assessment and intervention in developmental context. Kingston, NJ: Civic Research Institute) that may indicate additional risk for ADHD. Hence, we examined whether baseline PS moderates the association between preschoolers' PA, specifically moderate-to-vigorous PA (MVPA), and changes in ADHD levels and related behaviors.

Method: Eighty-five preschoolers (49.4% female; M_age = 4.14, SD_age = .64) were drawn from a larger study of the effects of the Kiddie Children and Teachers (CATs) on the Move PA program on school readiness. The sample was largely Head Start eligible (68.2%) and ethnically diverse. Hierarchical regressions were utilized to examine links between MVPA, averaged over a school year, and changes in inattention (IA), hyperactivity/impulsivity (HI), oppositional behaviors, moodiness, and peer functioning, and whether these associations varied based on baseline PS.

Results: Results indicated that for IA, HI, and peer functioning, higher amounts of MVPA were associated with greater adaptive change for those with lower (but not higher) levels of PS.

Conclusions: Preschool MVPA may be a viable method of reducing ADHD levels and impairments for those with lower PS.

Keywords: Attention-deficit/hyperactivity disorder (ADHD); early intervention; moderate-to-vigorous physical activity (MVPA); physical activity (PA); preschool; prevention; processing speed (PS).