Lifelong greenspace exposure and ADHD in Polish children: Role of physical activity and perceived neighbourhood characteristics

Abstract

Previous research found a protective association between greenspace exposure and attention deficit hyperactivity disorder (ADHD) diagnosis, but previous studies did not investigate mediatory pathways involving child physical activity (PA) and environmental perceptions. Here, we examined the association between lifelong exposure to greenspace and ADHD diagnosis and potential underlying mechanisms (i.e., perceived greenspace, PA, neighbourhood social cohesion, and neighbourhood safety) in children aged 10-13 with and without ADHD. The sample (N = 689) was collected within the NeuroSmog case-control study, where children with (N = 203) and without ADHD (N = 486) were recruited from 18 towns in Southern Poland. ADHD diagnosis was ascertained according to the International Classification of Diseases 11th Revision criteria. Greenspace exposure was defined as the percentage of grass and tree cover in 500 m and 1 km buffers around lifelong residential addresses, respectively. Parents reported information about the availability of domestic garden and data on potential mediators was collected with questionnaires. Structural equation modeling was used to examine hypothesized pathways, and their interplay, linking the three greenspace measures to ADHD. We found that greenspace was indirectly related to ADHD diagnosis: tree cover was positively related to PA, and PA was subsequently negatively related to ADHD diagnosis. Tree cover and garden were both associated with higher levels of perceived greenspace, which in turn related to stronger perceptions of neighbourhood social cohesion. Our findings suggest that exposure to greenspace may lead to lower likelihood of ADHD diagnosis indirectly through PA. These findings highlight how providing children with better access to natural environments for PA may support normal neurodevelopment.