The Scientific Basis of Attention Deficit Hyperactivity Disorder in Adults

Abstract

(from the chapter) This chapter discusses the scientific basis of attention deficit hyperactivity disorder in adults. In adults, prevalence estimates range from 2.5 to 4.3%. Recent data on prescription rates of drug treatments for attention deficit hyperactivity disorder (ADHD) in the UK suggest that there is a marked reduction in the numbers of individuals treated beyond 18 years of age, which does not reflect what is known about the natural course of the disorder and is far in excess of that predicted by remission rates. The wide range in prevalence rates cited in the literature almost certainly reflects differences in the way that ADHD symptoms have been measured and the way that operational criteria have been applied across the different studies. Symptom thresholds for ADHD are difficult to define with any degree of certainty because they lie on a continuum in the general population, which means there is no natural boundary between affected and unaffected individuals. Definitions of ADHD also depend critically on the way that impairment and pervasiveness across situations are defined. This was demonstrated in a study of 7 and 8-year-olds from Newcastle, which found a prevalence of 11.1% when symptom count alone was used to define the disorder, 6,7% when an impairment score Children's Global Assessment of Functioning Scale was applied, 4.2% with a more severe impairment threshold, and only 1.4% when pervasiveness was also taken into account. (PsycINFO Database Record (c) 2014 APA, all rights reserved).