What is ADHD? Robert D. Smith, PhD Attention-deficit/hyperactivity disorder (ADHD) is a developmental brain disorder with symptoms of hyperactivity, impulsiveness and/or inattention. Many of the symptoms of ADHD occur from time to time in everyone. For people with ADHD, the number and frequency of these symptoms is greater than most people and significantly impairs educational achievement, career success and life success in general. Symptoms The distinct symptom DSM-5 categories of ADHD are: Impulsiveness: acting before thinking of consequences, jumping from one activity to another, disorganization, tendency to interrupt other peoples' conversations. Hyperactivity: restlessness, often characterized by an inability to sit still, fidgeting, squirminess, climbing on things, restless sleep. Inattention: easily distracted, day-dreaming, not finishing work, difficulty listening. The DSM-V identifies three ADHD subtypes: (1) Inattentive; (2) hyperactive/impulsive; and (3) combined. There is growing discussion between experts that the inattentive type may be two different types. A Unique ADD Type, not yet officially recognized is a distinctly different information processing disorder characterized by sluggish cognitive tempo. Diagnosis is based on criteria specified in the DSM-V or the ICD-10. No objective test has been identified as sufficient evidence to make a diagnosis of ADHD. Diagnosis is therefore based on clinical judgment. However, neuropsychological tests can provide significant objective evidence supporting clinical judgment. In addition, impairment of executive functioning is often present. The International Statistical Classification of Diseases and Related Health Problems (ICD-10) are published by the World Health Organization. The ICD-10 provides criteria and codes to classify diseases. The American Psychiatric Association used the general outline of mental disorder classifications in the ICD-10 and tried to improve the diagnostic criteria and developed the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). In North America, the DSM-V criteria are used to make a diagnosis of ADHD, while European countries usually use the ICD-10. Previous editions of the ICD series have used the term Attention Deficit Disorder (ADD) with and without hyperactivity/impulsiveness. The DSM-V has adopted the term Attention Deficit/Hyperactivity Disorder (ADHD) with and without hyperactivity/impulsiveness. The two terms mean essentially the same thing and have resulted in confusion. However, the use of the term ADD to refer to ADHD, predominantly inattentive type makes good common sense.