Etiologies of ADHD

Abstract

It should be evident from the research reviewed here that neurological and genetic factors make a substantial contribution to symptoms of ADHD and the occurrence of the disorder. A variety of genetic and neurological etiologies can give rise to the disorder, likely through some disturbance in a final common pathway in the nervous system. That final common pathway appears to date to be the integrity of the prefrontal cortical-striatal-cerebellar network. It now appears that hereditary factors play the largest role in the occurrence of ADHD symptoms in children. Yet the condition can also be caused or exacerbated by pregnancy complications, exposure to toxins, or neurological disease. Social factors alone are not supported as causal of this disorder, but such factors may possibly interact with genetic risks for the disorder and may contribute to the forms of comorbid disorders associated with ADHD. Cases of ADHD can also arise without a genetic predisposition to the disorder provided the child is exposed to significant disruption or neurological injury to this final common neurological pathway. But this would seem to account for only a small minority of children with ADHD. In general, then, research conducted since the previous edition of this volume was published has further strengthened the evidence for genetic and developmental neurological factors, along with biohazardous events during brain development, as likely causing this disorder, while greatly reducing the support for the role of purely social factors in causing ADHD. (PsycInfo Database Record (c) 2021 APA, all rights reserved) (Source: chapter)