When the American Psychiatric Association (APA) released its first Diagnostic and Statistical Manual of Mental Disorders (DSM) in 1952, many of today’s most common pediatric diagnoses had yet to be invented. “Attention deficit disorder” (ADD) did not make its first DSM appearance until 1980, when the APA established it as a pediatric neurobehavioral disorder characterized by problems with inattention, impulsivity or hyperactivity. (ADD’s DSM precursor, “hyperkinetic reaction of childhood,” focused mostly on excessive motor activity.) In 1987, the APA replaced ADD with “attention deficit hyperactivity disorder” (ADHD), which is now the most commonly diagnosed childhood neurodevelopmental disorder. The most recent DSM also allows for a dual ADHD-autism diagnosis, recognizing that anywhere from one-fifth to one-half of children with ADHD meet the criteria for autism spectrum disorder (ASD).