Is attention-deficit/hyperactivity disorder an energy deficiency syndrome?

Attention-deficit/hyperactivity disorder (ADHD) is a highly heritable yet c linically heterogeneous syndrome associated with hypocatecholamine function in subcortical and prefrontal cortical regions and clinical response to me dications that enhance catecholamine function. The goal of this article is to present a hypothesis about the etiology of ADHD by synthesizing these fi ndings with recent experiments indicating that activity-dependent neuronal energy consumption is regulated by cortical astrocytes. The scientific lite rature was searched from 1966 to the present using MEDLINE and relevant key words. Inattention and impulsivity may be related to hypofunctionality of catecholamine projection pathways to prefrontal cortical areas, resulting i t? decreased neuronal energy availability. This may be mediated by astrocyt e catecholamine receptors that normally regulate energy availability during neuronal activation. At least some forms of ADHD may be viewed as cortical , energy-deficit syndromes secondary to catecholamine-mediated hypofunction ality of astrocyte glucose and glycogen metabolism, which provides activity -dependent energy to cortical neurons. Several tests of this hypothesis are proposed. (C) 2001 Society of Biological Psychiatry.