Not only does attention-deficit/hyperactivity disorder (ADHD) have one of the earliest known onsets of mental health disorders, but it is also the most prevalent among children and one of the most persistent. Its continuation into adulthood is now well documented. For this reason, the study of the lifespan of persons with ADHD has emerged as an important area of research on ADHD. With a median age of onset of 6.9 years, the symptoms of this condition are diverse, often debilitating, and include attentional problems, such as distractibility, forgetfulness, daydreaming, and disorganization, and behavioral manifestations such as fidgeting, impulsiveness, excessive activity, and talkativeness. One-year prevalence rates among children and adolescents in the United States range from 3% to 5%. Although genetic studies have reported that as ...