Specificity of inattention, impulsivity, and hyperactivity to the diagnosis of attention-deficit hyperactivity disorder.

Children with attention-deficit hyperactivity disorder (ADHD) were compared with non-ADHD psychiatric patients and normal controls on objective measures of inattention, impulsivity, and hyperactivity to determine the specificity of these symptoms to ADHD. Inattention and impulsivity were assessed using a continuous performance test, and activity was measured using solid state actigraphs. Both patient groups were inattentive relative to normals, but were indistinguishable from each other. However, the ADHD group was more active than both non-ADHD patients and normals, who did not differ from each other. These data suggest that inattention may be a nonspecific symptom of child psychiatric disorder. However, ADHD may be uniquely characterized by overactivity.