The evolution of ADHD: A disorder of communication?

Attention deficit hyperactivity disorder (ADHD) is the most commonly diagno sed psychiatric condition. Many believe that the central disability is impa ired inhibition, which leads to reduced abilities in social ski:ls, self-co ntrol, organization and time management. The behaviors identified by clinic ians ns problematic-inattention, hyperactivity and impulsivity-have been in corporated into, several evolutionary models as selectively adaptive cognit ive skills for surviving the challenges of a variable Pleistocene environme nt. We propose that the "disabilities" exhibited by individuals with ADHD a re maladaptive, and we concur with Barkley that there is a central impairme nt in the behavioral inhibition system. The underlying neural anatomy and p hysiology support the possibility that neurotransmitter pathology may have an impart on other interlinked sq systems (including management), and may a lso account for the frequent comorbidity of aggression, anxiety, depression , and learning disabilities (many of which are language-related). Language skills compete with other cognitive activities for the attentional system, and thus the evolution of language could not in fact be independent gi the evolution of attention. If language represents the ultimate expression of t he attentional system, and some individuals with ADHD are seriously impaire d in the coordination of interlinked neural systems (including language), t hen ADHD fits Jerome Wakefield's definition of "harmful dysfunction," and c ommunication impairments should be investigated more thoroughly by clinicia ns.