19 Chapter 7 Introduction

Attention-Deficit/Hyperactivity Disorder (ADHD) is a psychiatric disorder that is most often diagnosed in school-aged children. It is the most prevalent childhood psychiatric disorder in Canada (Centre for ADHD Awareness, Canada [CADDAC], n.d.). ADHD occurs in 3-5% of elementary-school aged children and is more common in males than females (Johnson, 2009). In Canada, each classroom will include at least 1 to 3 students with ADHD (CADDAC, n.d.). Furthermore, at least 50% of children with ADHD will continue to have symptoms in adolescence and adulthood (Bélanger, Andrews, Gray, & Korczak, 2018). Approximately 4% of adults experience at least some symptoms of ADHD (CADDAC, n.d.).

Many children with ADHD find it difficult to focus on tasks and follow instructions, and these characteristics can lead to problems in school and at home. How children with ADHD are diagnosed and treated is a topic of controversy, and many people, including scientists and nonscientists alike, hold strong beliefs about what ADHD is and how people with the disorder should be treated. This module will familiarize the reader with the scientific literature on ADHD. First, we will review how ADHD is diagnosed in children, with a focus on how mental health professionals distinguish between ADHD and normal behavior problems in childhood. Second, we will describe what is known about the causes of ADHD. Third, we will describe the treatments that are used to help children with ADHD and their families. The module will conclude with a brief discussion of how we expect that the diagnosis and treatment of ADHD will change over the coming decades.