When

‘The dopamine theory of attention deficit hyper-activity disorder (ADHD) ’ was published in the Aus-tralian and New Zealand Journal of Psychiatry [1], the predominant theory of ADHD was noradrenergic, pos-sibly because of the limited efficacy of l-dopa and dopamine agonists for symptoms of ADHD. Despite this, the animal data indicated a significant role for dopaminergic systems as reviewed in 1991 [1]. The intervening years have seen a number of advances in genetic, neuropsychological, pharmacological and brain imaging investigations of ADHD. The present review aims to outline these advances and examine ques-tions raised by them, such as the involvement of dopa-minergic and other neurotransmitter systems in ADHD. Also, ‘hyper ’ versus ‘hypo ’ dopaminergic theories, and the relationship between anterior and posterior attention systems are discussed. Recent reviews of the neuro-biology of ADHD [2,3] concluded that while there is no single pathophysiological profile of ADHD, many data implicate dysfunction in fronto-subcortical pathways, which control attention and motor behaviour. The effec-tiveness of stimulants, along with animal models, point to catecholamine dysregulation as at least one source of ADHD brain dysfunction [3]. Timing, space and ADHD: the dopamine theory revisite