When people think of impulsivity, they most often think about cognitive impulsivity which is acting without thinking. The impulsivity of children with AD/HD is slightly different. These children act before thinking because they have difficulty waiting or delaying gratification. Impulsivity leads these children to speak out of turn, interrupt others and engage in what looks like risk-taking behavior. The child may run across the street without looking or climb to the top of very tall trees. Although such behavior is risky, the child is not really a risk-taker but, rather, has great difficulty controlling impulse. Often the child is surprised to discover that he or she has gotten into a dangerous situation and has no idea of how to get out of it.

Symptoms of impulsivity as listed in the DSM-IV are:

  • Often blurts out answers before questions have been completed.
  • Often has difficulty awaiting turn.
  • Often interrupts or intrudes on others, (e.g., butts into conversations or games).

It is important to note that, in the DSM-IV, hyperactivity and impulsivity are no longer considered as separate features, According to Barkley (1990), hyperactivity-impulsivity is a pattern stemming from an overall difficulty in inhibiting behavior.

In addition to problems with inattention or hyperactivity-impulsivity, the disorder is often seen with associated features. Depending on the child's age and developmental stage, parents and teachers may see low frustration tolerance, temper outburst, bossiness, and difficulty in following rules, disorganization, social rejection, poor self-esteem, academic underachievement, and inadequate self-application (American Psychiatric Association, 1994).