Abstract
Attention-deficit hyperactivity disorder (ADHD) is a chronic neurodevelopmental disorder. Three position statements have been developed by the Canadian Paediatric Society, following systematic literature reviews. Statement objectives are to: 1) Summarize the current clinical evidence regarding ADHD,2) Establish a standard for ADHD care, and3) Assist Canadian clinicians in making well-informed, evidence-based decisions to enhance care of children and youth with this condition. Specific topics reviewed in Part 3, which focuses on associated autism spectrum disorder, intellectual disability, and prematurity, include the challenges of diagnostic assessment, common presentations, the role of genetics, and treatment, including the benefits of physical activity. Recommendations are based on current guidelines, evidence from the literature, and expert consensus.