The predominant features of ADHD

1. Impaired response inhibition, impulse control, or the capacity to delay gratification. This is often noted in the individual’s inability to stop and think before acting; to wait one’s turn while playing games, conversing with others, or having to wait in line; to interrupt their responding quickly when it becomes evident that their actions are no longer effective; to resist distractions while concentrating or working; to work for larger, longer-term rewards rather than opting for smaller, more immediate ones; and inhibiting the dominant or immediate reaction to an event, as the situation may demand.
2. Excessive task-irrelevant activity or activity that is poorly regulated to the demands of a situation. Individuals with ADHD in many cases are noted to be excessively fidgety, restless, and “on the go.” They display excessive movement not required to complete a task, such as wriggling their feet and legs, tapping things, rocking while seated, or shifting their posture or position while performing relatively boring tasks. Younger children with the disorder may show excessive running, climbing, and other gross motor activity. While this tends to decline with age, even teenagers with ADHD are more restless and fidgety than their peers. In adults with the disorder, this restlessness may be more subjective than outwardly observable, although with some adults they remain outwardly restless as well and report a new to always be busy or doing something and being unable to sit still.
3. Poor sustained attention or persistence of effort to tasks. This problem often arises when the individual is assigned boring, tedious, protracted, or repetitive activities that lack intrinsic appeal to the person. They often fail to show the same level of persistence, “stick-to-it-tiveness,” motivation, and will-power of others their age when uninteresting yet important tasks must be performed. They often report becoming easily bored with such tasks and consequently shift from one uncompleted activity to another without completing these activities. Loss of concentration during tedious, boring, or protracted tasks is commonplace, as is an inability to return to their task on which they were working should they be unexpectedly interrupted. Thus, they are easily distracted during periods when concentration is important to the task at hand. They may also have problems with completing routine assignments without direct supervision, being unable to stay on task during independent work.

These are the three most common areas of difficulty associated with ADHD. However, research is suggesting that those with ADHD, particularly the subtypes associated with impulsive behavior (see below), may also have difficulties in the following areas of psychological functioning as well:

1. Remembering to do things, or working memory. Working memory refers to the capacity to hold information in mind that will be used to guide one’s actions, either now, or at a later time. It is essential for remembering to do things in the near future. Those with ADHD often have difficulties with working memory and so are described as forgetful around doing things, unable to keep important information in mind that they will need to guide their actions later, and disorganized in their thinking and other activities as they often lose track of the goal of their activities. They may often be described as acting without hindsight or forethought, and being less able to anticipate and prepare for future events as well as others, all of which seem to be dependent on working memory. Recently, research suggests that those with ADHD cannot sense or use time as adequately as others in their daily activities, such that they are often

late for appointments and deadlines, ill-prepared for upcoming activities, and less able to pursue long-term goals and plans as well as others. Problems with time management and organizing themselves for upcoming events are commonplace in older children and adults with the disorder.

2. Delayed development of internal language (the mind’s voice) and rule-following. Research has lately been suggesting that children with ADHD are significantly delayed in the development of internal language, the private voice inside one’s mind that we employ to converse with ourselves, contemplate events, and direct or command our own behavior. This private speech is absolutely essential to the normal development of contemplation, reflection, and self-regulation. Its delay in those with ADHD contributes to significant problems with their ability to follow through on rules and instructions, to read and follow directions carefully, to follow through on their own plans, rules, and “do- lists,” and even to act with legal or moral principles in mind. When combined with their difficulties with working memory, this problem with self-talk or private speech often results in significant interference with reading comprehension, especially of complex, uninteresting, or extended reading assignments.
3. Difficulties with regulation of emotions, motivation, and arousal. Children and adults with ADHD often have problems inhibiting their emotional reactions to events as well as do others of their age. It is not that the emotions they experience are inappropriate, but that those with ADHD are more likely to publicly manifest the emotions they experience than would someone else. They seem less able to “internalize” their feelings, to keep them to themselves, and even to moderate them when they do so as others might do. Consequently, they are likely to appear to others as less emotionally mature, more reactive with their feelings, and more hot-headed, quick-tempered, and easily frustrated by events. Coupled with this problem with emotion regulation is the difficulty they have in generating intrinsic motivation for tasks that have no immediate payoff or appeal to them. This capacity to create private motivation, drive, or determination often makes them appear to lack will-power or self-discipline as they cannot stay with things that do not provide immediate reward, stimulation, or interest to them. Their motivation remains dependent on the immediate environment for how hard and how long they will work, whereas others develop a capacity for intrinsically motivating themselves in the absence of immediate rewards or other consequences. Also related to these difficulties with regulating emotion and motivation is that of regulating their general level of arousal to meet situational demands. Those with ADHD find it difficult to activate or arouse themselves to initiate work that must be done, often complain of being unable to stay alert or even awake in boring situations, and frequently seem to be daydreamy or “in a fog” when they should be more alert, focused, and actively engaged in a task.
4. Diminished problem-solving ability, ingenuity, and flexibility in pursuing long-term goals. Often times, when we are engaged in goal-directed activities, problems are encountered that are obstacles to the goal’s attainment. At these times, individuals must be capable of quickly generating a variety of options to themselves, considering their respective outcomes, and selecting among them those which seem most likely to surmount the obstacle so they can continue toward their goal. Persons with ADHD find such hurdles to their goals to be more difficult to surmount; often giving up their goals in the face of obstacles and not taking the time to think through other options that could help them succeed toward their goal. Thus they may appear as less flexible in approaching problem situations, more likely to respond automatically or on impulse, and so are less creative at overcoming the road-blocks to their goals than others are likely to be. These problems may even be evident in the speech and writing of those with the disorder, as they are less able to quickly assemble their ideas into a more organized, coherent explanation of their thoughts. And so they are less able to rapidly assemble their actions or ideas into a chain of responses that effectively accomplishes the goal given them, be it verbal or behavioral in nature.
5. Greater than normal variability in their task or work performance. It is typical of those with ADHD, especially those subtypes associated with impulsive behavior, to show substantial variability across time in the performance of their work. These wide swings may be found in the quality, quantity, and even speed of their work, failing to maintain a relatively even pattern of productivity and accuracy in their work from moment to moment and day to day. Such variability is often puzzling to others who witness it as it is clear that at some times, the person with ADHD can complete their work quickly and correctly while at others times, their tasks are performed poorly, inaccurately, and quite erratically. Indeed, some researchers see this pattern of high variability in work-related activities to be as much a hallmark of the disorder as is the poor inhibition and inattention described above.