Europe continued to view hyperkinesis for most of the latter half of the 20th century as a relatively rare condition of extreme overactivity often associated with mental retardation or evidence of organic brain damage.

This discrepancy in perspectives has been converging over the last decades as is evident in the similarity of the DSM-IV criteria (see below) with those of ICD-10 (World Health Organization, 1994).

Significant, historically, was the distinction in DSM-III between two types of ADD: those with hyperactivity and those without it.

Little research existed at the time on the latter subtype that would have supported such a distinction being made in an official and increasingly prestigious diagnostic taxonomy.

Further serious clinical interest in ADHD did not occur again until the appearance of three lectures by the English physician George Still (1902) before the Royal Academy of Physicians. Described as aggressive, passionate, lawless, inattentive, impulsive, and overactive, many of these children today would be diagnosed not only as ADHD but also as having oppositional defiant disorder (ODD).

Still reported on a group of 20 children in his clinical practice whom he defined as having a deficit in “volitional inhibition” (p. Still’s observations were quite astute, describing many of the associated features of ADHD that would come to be corroborated in research over the next century: (1) an overrepresentation of male subjects (ratio of 3:1 in Still’s sample); (2) high comorbidity with antisocial conduct and depression; (3) an aggregation of alcoholism, criminal conduct, and depression among the biological relatives; (4) a familial predisposition to the disorder, likely of hereditary origin; (5) yet with the possibility of the disorder also arising from acquired injury to the nervous system.

These cases and others known to have arisen from birth trauma, head injury, toxin exposure, and infections (see Barkley, 2006) gave rise to the concept of a brain-injured child syndrome (Strauss & Lehtinen, 1947), often associated with mental retardation, that would eventually become applied to children manifesting these same behavior features but without evidence of brain damage or retardation (Dolphin & Cruickshank, 1951; Strauss & Kephardt, 1955).

This concept evolved into that of minimal brain damage, and eventually minimal brain dysfunction (MBD), as challenges were raised to the original label in view of the dearth of evidence of obvious brain injury in most cases (see Kessler, 1980, for a more detailed history of MBD).

Despite a continuing belief among clinicians and researchers of this era that the condition had some sort of neurological origin, the larger influence of psychoanalytic thought held sway.

And so, when the second edition of Diagnostic and Statistical Manual of Mental Disorders (DSM-II) appeared, all childhood disorders were described as “reactions,” and the hyperactive child syndrome became “hyperkinetic reaction of childhood” (American Psychiatric Association, 1968).

Current critical issues related to these matters will be raised along the way. Literary references to individuals having serious problems with inattention, hyperactivity, and poor impulse control date back to Shakespeare, who made reference to a malady of attention in King Henry VIII.

Given the thousands of scientific papers on this topic, this course must, of necessity, concentrate on the most important topics in this literature. A hyperactive child was the focus of a German poem, “Fidgety Phil,” by physician, Heinrich Hoffman (see Stewart, 1970).

The recognition that the disorder was not caused by brain damage seemed to follow a similar argument made somewhat earlier by the prominent child psychiatrist Stella Chess (1960).