Attention deficit hyperactivity disorder (ADHD), characterized by inattention, hyperactivity and impulsivity, is an early onset, highly heritable, clinically heterogeneous, long-term impairing disorder with tremendous impact on individuals, families, and societies. It affects 5-10% of school-aged children worldwide (7.5% in Taiwan) and 2-4% of adults. Neuropsychological deficits related to executive functions, state regulation, and delay aversion show heritability, replicated association with ADHD, and familial-genetic overlap with ADHD, are suitable for biomarkers for ADHD. Despite the abundance of molecular genetic studies on ADHD, the genetic etiologies of ADHD have been non-conclusive, and there is limited information about the expressions, neuropsychological deficits, and genetic variants for ADHD in Chinese population. This present study, a family-based parental control association study, aims to identify the genetic markers of dopaminergic and noradrenergic systems for ADHD using the dichotomous categorization of affected and non-affected, quantitative phenotypes (symptom dimension and severity of ADHD) and endophenotype (neuropsychological measures) as well.