attention deficit disorder

:  a developmental disorder that is marked especially by persistent symptoms of inattention (such as distractibility, forgetfulness, or disorganization) or by symptoms of hyperactivity and impulsivity (such as fidgeting, speaking out of turn, or restlessness) or by symptoms of all three and that is not caused by any serious underlying physical or mental disorder ◆Symptoms of attention deficit disorder range from mild to severe and always interfere with normal development and daily functioning. A diagnosis of attention deficit disorder typically requires that symptoms be present by the age of 12 and in more than one setting (such as both home and school). Attention deficit disorder may persist into adulthood, creating difficulties in one's occupation or social relationships. While hyperactivity and impulsivity are not always present as symptoms, attention deficit disorder is commonly referred to as attention deficit hyperactivity disorder. Three percent to 10 percent of children are estimated to have attention deficit disorder, and the problem is more common in boys than in girls.—The Springfield (Massachusetts) Union-News, 8 Apr. 1993—abbreviation ADD