The effect of physical activity interventions on executive functions in children with ADHD: A systematic review and meta-analysis

Background: Attention-deficit hyperactivity disorder (ADHD) is a commonly diagnosed behavioral disorder in school-aged children. A core symptom of ADHD is difficulties with executive functions (EF). Physical activity (PA) interventions are proposed to be a valuable addition to traditional treatment approaches for ADHD. This systematic review examined the evidence for the effect of chronic PA on EF, specifically, inhibition, shifting, working memory, and attention in children with ADHD compared to no treatment. The moderating impact of PA cognitive demand and methylphenidate (MPH) treatment on the effect of PA interventions on EF was also examined. Methods: A systematic review and meta-analyses were conducted following the Cochrane Guidelines for Systematic Reviews. A protocol was published with PROSPERO (CRD42018099617); seven databases were searched, and 3690 results screened by two independent researchers. Based on inclusion and exclusion criteria, 12 eligible studies were included, and separate meta-analyses were conducted for each EF domain, each including subgroups of high vs low cognitive demand, and MPH-intake vs. MPH-free. Results: Results showed beneficial effects of PA for all EF, with 95%-CI compatible with positive effects for shifting (SMD = -1.58; 95%-CI (-3.12; -0.041) and working memory (SMD = -0.99; 95%-CI (-1.80; -0.181) only. Cognitive demand of PA differed in its impact depending on the domain of EF. Benefits of PA were lesser in those taking MPH, though subgroup differences were statistically non-significant. Conclusion: Children with ADHD benefit from PA leading to enhanced executive functioning performance. However, the cognitive demands of the PA need to be considered when contemplating PA as an adjunctive treatment option.