Follow‐ups of children with attention delicit hyperactivity disorder (ADHD)
Authors: Lie Nils 
Published: August 2007

The development of a syndrome most often referred to as Minimal Brain Dysfunction (MBD), the Hyperactive (Hyperkinetic) Syndrome, Attention Deficit Disorder (ADD), and Attention Deficit Hyperactivity Disorder (ADHD) shows that almost identical conditions have been named differently, whereas identical labels have been used for different conditions, with several unfortunate consequences.

The pioneering research was carried out on patient populations, drawn from private practice as well as from hospitals. This has influenced the description of the syndrome(s) Neurologists have described a disorder which is different from that observed by child psychiatrists.

Since it is subjects with concurrent ADHD and conduct problems who represent problems to parents and teachers, whereas those with ADHD but with normal conduct do not, it is the former who are referred for treatment. In the United States, these children were studied, and rating scales for the Hyperactive Syndrome were developed according to their symptoms. Early conduct problems were incorrectly interpreted as symptoms of ADHD.

The difference between European and US diagnostic practices is most clearly shown in epidemiological studies. In U.S. publications, it has been purported that 50% of children are at risk for MBD, and that 75% of all child psychiatric patients were suffering from a Hyperactive Syndrome. The corresponding frequencies in Europe have been 1‐2% and 1.5% respectively. About ten years ago. US. child psychiatrists noted that they had used the diagnosis too frequently and that the European practice and the epidemiological findings reported from Europe were correct This has been considered in DSM‐III and DSM‐III‐R.

Considering that up to 75% of patients in Child Psychiatric Clinics were diagnosed as suffering from a Hyperactive syndrome, whereas the correct rate would have been 1‐2%, it is obvious that in U.S. projects prior to 1980, few if any of U.S. child psychiatric patients had ADHD according to the present criteria. Some had ADHD in addition to conduct problems. Most had probably conduct problems (not the full CD syndrome) with situational (not pervasive) hyperactivity without ADHD.

The socalled “hyperactives” did not have Conduct Disorder (CD). This diagnosis requires symptoms such as stealing, forgery, armed robbery, truancy from school or absence from work, rape, use of weapon. Obviously, this is a diagnosis which is not adequate for preschool children. However, children who were incorrectly diagnosed as hyperactive had unpredictable show of affection, were unpredictable, unresponsive to discipline, and could not accept correction. They were defiant, irritable, reckless, unpopular with peers, accident prone and destructive. They lied, teased and fought. It appears that these features are symptoms of a pre‐CD.

Formerly, is was purported that ADHD and CD were in fact one syndrome. However, as a consequence of improved methodology, it has during recent years been possible to show that ADHD and CD are different disorders; differing regarding etiology as well as prognosis. However. it appears that questionnaires are too insensitive instruments for such a differentiation. When longitudinal studies regarding ADHD are reviewed, and findings are interpreted, it is necessary to consider whether the subjects had ADHD, conduct problems (i.e. pre‐CD), or a mixture of both disorders. Otherwise. the results will be totally misleading.

The revieved projects have without exception been carried out in North America. The studies started at a time when the U.S. criteria of the “Syndrome” was very “broad” and when 30‐ 75 percent of all U.S. child psychiatric patients were diagnosed hyperactive, compared to 1‐2 percent in Great Britain. It has been shown in the introduction that the “Syndrome” was diagnosed far too often in the United States, and that the European concept is the correct one. Consequently, the majority of the cases in long‐term studies, at least those drawn from patient populations, probably did not have a “true”“Syndrome”, i.e. they did not have exclusively ADHD. Only a minority appears to have had ADHD, whereas most had conduct problems with or without ADHD.

The most outstanding advantages and shortcomings of the projects to be reviewed will be briefly summarized:

The differences in the Tables may represent true differences More probably, they are the consequence of subjects with educational and conduct problems in childhood being compared to controls without a childhood history of such problems, i.e the differences may not be related to ADHD at all

The results presented in the previous chapter have been supported by additional studies cited in this chapter.