Clinical and neurobiological features of the attention deficit hyperactivity disorder

Objective: To present the state-of-the-art regarding the clinical and neurobiological features of the attention deficit and hiperactivity disorder. Development: The general concepts of this disorder including its definition, its comorbidities, its epidemiology, its psychosocial treatment as well as its implications are reviewed. An analysis of the neuroimaging evidences used in diagnosis of this disorder, and the data obtained from the genetic linkage studies, provide a possible etiology in a deficit of the cerebral catecholaminergic system, specifically the D4 dopamine receptor and its transporter. The hypothesis of the consequences of this defect in the sintomatology of the disorder is examined. Conclusions: Research on genetic bases of the attention deficit and hiperactivity disorder will help clarify its phisiopathology and its definition too.