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What is Attention Deficit/Hyperactivity Disorder?

Definitions of Attention Deficit/Hyperactivity Disorder

The essential feature of Attention-Deficit/Hyperactivity Disorder is a persistent pattern of inattention or hyperactivity-impulsivity that is more frequently displayed and more severe than is typically observed in individuals at a comparable level of development. The disturbance does not occur exclusively during the course of a pervasive developmental disorder, schizophrenia, or other psychotic disorder and is not better accounted for by another mental disorder (e.g., a Mood Disorder, Anxiety Disorder, Dissociative Disorder, or Personality Disorder).
(American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC, American Psychiatric Association. 2000)

Attention deficit-hyperactivity disorder (ADHD) is a neurobehavioral disorder that affects 3-5 percent of all American children. It interferes with a person's ability to stay on a task and to exercise age-appropriate inhibition (cognitive alone or both cognitive and behavioral). Some of the warning signs of ADHD include failure to listen to instructions, inability to organize oneself and school work, fidgeting with hands and feet, talking too much, leaving projects, chores, and homework unfinished, and having trouble paying attention to and responding to details. There are several types of ADHD: a predominantly inattentive subtype, a predominantly hyperactive-impulsive subtype, and a combined subtype. ADHD is usually diagnosed in childhood, although the condition can continue into the adult years.
(National Institute of Mental Health [NIMH], nimhinfo@hil.gov)