Biological contributions to the presentation and understanding of attention-deficit/hyperactivity disorder: a review

Attention-deficit/hyperactivity disorder (ADHD) is the most commonly diagnosed disorder in children today with estimated prevalence rates falling between 3 and 5% of children (American Psychiatric Association, 1994). From inception, research has focused on studying varying facets of this disorder with initial efforts primarily focusing on treatment outcome. However, prominent efforts have been made in recent research efforts to shed light on the etiology of this disorder. Such research has discovered the contribution of genetic inheritance, as well as environmental factors that lead to the development of this disorder. Furthermore, studies using neurological and neuropsychological assessment measures have implicated the involvement of various Parts of the brain. This article critically reviews this body of research in light of its impact on the current specific neuropsychologically based etiological theories, as well as the most beneficial directions for future research.