ADHD and the Nature of Self-Control

ADHD and the Nature of Self-Control

Barkley RA

New York: The Guilford Press; 1997. 410 pp with index

ISBN 1-57230-250-X (cloth)

Attention deficit disorder is the most thoroughly researched psychiatric condition that affects children. There have been thousands of scientific reports on this condition, from the story of fidgety Phil written by the German physician Heinrich Hoffmann some 150 years ago to a study of 20 children by George Still, published in the Lancet in 1902, in which he described what it was like to have a deficit of “volitional inhibition” or “defect of moral control of their behaviour.” However, virtually all work has been atheoretical; authors describe the epidemiology, clinical symptoms, specific behavioural and cognitive deficits or treatment approaches of these youngsters, but offer no theory on the underlying cause.

Dr. Barkley, a highly respected researcher and clinician in the area of attention deficit/hyperactivity disorder (ADHD), is trying to change this, and in this volume lays out a thought provoking and sophisticated theory of ADHD.

He takes the reader through the last 50 years of work on ADHD and ends his review by concluding that there are 2 forms of sustained attention: one that is context dependent, contingency shaped or externally controlled, and one that is goal directed and internally guided. Barkley claims that children with ADHD only have difficulties with the second type and therefore suffer from a central deficit of behavioural inhibition. This function, according to Dr. Barkley, is necessary for the development of 4 executive functions, which in turn allow us to modulate our experiences and behaviour through effective internal controls. Brief descriptions of these 4 executive functions follow.

Non-verbal working memory. This function allows us to hold events in our minds, to manipulate or act on events mentally, to have hindsight and foresight, to anticipate the future and to have a sense of time and self-awareness.

Verbal working memory. This includes an internalization of speech and allows for description and reflection, problem solving, self-questioning and effective generation of rules and moral reasoning.

Self-regulation of affect, motivation and arousal. This allows us to practise emotional self-control and gives us social perspective and a sense of long-range planning.

Reconstruction. This function supports an analysis and synthesis of behaviour, verbal and behavioural fluency, behavioural creativity and diversity as well as behavioural simulation.

Dr. Barkley convincingly argues that deficits in these executive functions can lead to problem behaviour and poor motor control, primarily because of impaired goal-directed persistence or responses, a lack of behavioural flexibility and insufficient inhibition of tasks to relevant responses.

He supports his arguments by citing various studies that have documented specific cognitive weaknesses or deficits in children with ADHD that could reflect problems in specific executive functions. However, there have not been any studies that have looked at a wide range of executive function tests in a good sized population of ADHD children. Hence Dr. Barkley’s theory has not yet been empirically proven. As far as the difficulties are concerned, Dr. Barkley sees the central deficit of children with ADHD to be biological and located in the prefrontal lobe. This is based on a number of studies that have shown a smaller size or less blood flow to this area in children with ADHD. The “prefrontal lobe area causation theory” fits with Dr. Barkley’s conceptualization of the brain. In particular, he stresses that the cerebral cortex is concerned with the mental representation of the outside world and that the temporal, parietal and occipital regions form and store these representations. The prefrontal lobe, in turn, is seen as an area that activates the other regions as needed, or holds them in line for guiding future responses. Specifically, he thinks that this area of the brain shows maturational deficits in children with ADHD that are primarily inherited and only very rarely the result of specific traumatic events.

Dr. Barkley’s theory has implications not only for the diagnosis of ADHD but also for its treatment. Specifically, stimulant medication is advocated to improve behavioural inhibition and thus allow for a strengthening of the 4 executive functions. Furthermore, the deficit in using internally represented forms of information to direct behaviour is best dealt with by externalizing information and making it relevant and interesting for the child. For example, Dr. Barkley suggests that teachers and parents use external prompts, cues, or reminders (e.g., a sign at the door saying “Have you turned off the light?”) to keep children with ADHD focused. He even suggests that rules and directions can be tape-recorded and played while the child works.

Another recommendation is to move interventions out of the office to the place where the behaviour is likely to take place. This allows immediate reinforcements and rewards to occur where they will be most effective.

The sense of time and its passage also need to be externalized to help deficits of reconstruction. This can be done by making the concept of time concrete with the help of eggtimers and by disassembling past events into smaller segments and recombining them into more useful and practical modules.

It follows that ADHD is seen as a chronic disability and that the learning that takes place while a child is taking methylphenidate (Ritalin) will usually not be helpful once the medication is discontinued. While Dr. Barkley stresses the developmental aspects of ADHD

— he underlines the fact that different children show different degrees of deficits in their executive functions and that some aspects of the condition improve with the maturation of the central nervous system — ADHD is still seen as a lifelong condition.

Dr. Barkley’s theory is intriguing and challenges much of our traditional thinking. In fact, few clinicians will dispute the fact that children with ADHD have many of the deficits described here and that our current treatments often do not adequately address them. The treatment implications of the theory — the use of stimulants in combination with psycho-educational measures that aim to externalize information and motivation

— are also important and valuable. However, all of these suggestions assume that the patient will be at least moderately cooperative and willing to work with parents or teachers in a common struggle against the negative consequences of ADHD. Dr. Barkley’s suggestions do not tell us how to win out over the external and potentially illegal rewards (e.g., stealing or drug use) emanating from the behaviour of problematic peers. The theory also does not sufficiently differentiate the deficits of children with ADHD from those with other cerebral dysfunctions who show similar disabilities but who respond more successfully to selective serotonin reuptake inhibitors.

Despite these questions, I found Dr. Barkley’s book to be both informative and fascinating. It makes us rethink an age-old question and, helped by the precise and clear writing of the author, allows us to marvel at the complexities of our feelings and thoughts. I recommend it highly to anyone who deals with children with ADHD in a professional capacity.