Throughout the past two decades, Russell Barkley has been among the most productive scientists and prolific writers in the field of attention-deficit hyperactivity disorder (ADHD). In ADHD and the Nature of Self-Control, he takes on the ambitious task of synthesizing a voluminous literature associated with ADHD, integrating it with writings in philosophy, neuropsychology, and child development and articulating what he refers to as a unified theory of ADHD.

Barkley posits that children with ADHD have a core deficit in inhibitory control, which prevents them from optimally using their "executive functions," which are mediated via the prefrontal cortex. Poor use of time, whether in the form of impulsive responding or lack of hindsight and foresight, are central features of Barkley's theory.

Barkley is not the first to propose that prefrontal cortex and executive function deficits are central to the pathology seen in children with ADHD. However, he goes well beyond others by presenting data to support the existence of four distinct components of executive functions: nonverbal working memory; internalization of speech; self-regulation of affect, motivation, and arousal; and reconstitution. He clearly defines each of these domains, describes how each might be affected by impaired inhibitory control, and discusses how these deficiencies are likely to affect behavioral and cognitive functioning.

Most of author's ideas presented in this book have been previously published in the scientific literature (1). However, for the interested reader, this book expands on Barkley's previously published works by more clearly describing the genesis of his theory, placing his ideas within a developmental neuropsychological framework, elaborating the social and political implications of his theory, and, very important, more carefully pointing out new directions for research.

The final chapter is notable in that it not only eloquently wraps up the book but also addresses several highly charged scientific and political issues related to ADHD. According to the author's theory, and to data from other investigators, children with this disorder do not have a primary deficit in attention. Thus he proposes that when the next iteration of DSM is published, the name for the disorder should be changed; the central component of "attention deficit" should not be maintained.

Barkley also convincingly argues that ADHD is a neurological disorder with a substantial genetic component. As such, he takes on those who claim that ADHD is a result of poor parenting, social ills, or just bad children. In particular, he goes after those who purport that stimulant medication is medically or ethically inappropriate for treating children with ADHD. He maintains that stimulant medication should be an important part of the treatment for ADHD, and he implies that not considering medication borders on malpractice.

Many of the ideas presented in ADHD and the Nature of Self-Control are highly sophisticated. Yet the book is extremely reader friendly. It feels as if Dr. Barkley is speaking to the reader rather than writing in the crisp, highly technical style of the scientific literature. All terms are clearly explained, and the reader is carefully walked through all logical leaps. This style is clearly an attribute of the book. However, for the reader more familiar with Barkley's thinking, it sometimes might feel long-winded or redundant.

Overall, this book presents what could be considered the first comprehensive theory of attention-deficit hyperactivity disorder. While much of what Barkley proposes might turn out to be true, undoubtedly, with time and the collection of additional data, aspects of his theory will need to be modified. Nonetheless, the book is a valuable contribution to the literature in that it leads to numerous testable hypotheses, and as such, it is likely to stimulate thinking, empirical research, and controversy well into the 21st century.

Dr. Halperin is professor of psychology at Queens College of the City University of New York in Flushing.