Introduction . Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by excessive amounts of inattention, hyperactivity, and impulsivity that are pervasive, impairing in multiple contexts, and otherwise age-inappropriate [ 1 , 2 , 3 ]. A recent meta-analysis reported a pooled ADHD prevalence of 7.2% (95% CI: 6.7–7.8%) among children in the world [ 4 ]. Similarly, the overall pooled ADHD prevalence in China was 6.26% (95% CI: 5.36–7.22%) [ ...