Impulsiveness as a timing disturbance: neurocognitive abnormalities in attention-deficit hyperactivity disorder during temporal processes and normalization with methylphenidate.

Full Abstract

We argue that impulsiveness is characterized by compromised timing functions such as premature motor timing, decreased tolerance to delays, poor temporal foresight and steeper temporal discounting. A model illustration for the association between impulsiveness and timing deficits is the impulsiveness disorder of attention-deficit hyperactivity disorder (ADHD). Children with ADHD have deficits in timing processes of several temporal domains and the neural substrates of these compromised timing functions are strikingly similar to the neuropathology of ADHD. We review our published and present novel functional magnetic resonance imaging data to demonstrate that ADHD children show dysfunctions in key timing regions of prefrontal, cingulate, striatal and cerebellar location during temporal processes of several time domains including time discrimination of milliseconds, motor timing to seconds and temporal discounting of longer time intervals. Given that impulsiveness, timing abnormalities and more specifically ADHD have been related to dopamine dysregulation, we tested for and demonstrated a normalization effect of all brain dysfunctions in ADHD children during time discrimination with the dopamine agonist and treatment of choice, methylphenidate. This review together with the new empirical findings demonstrates that neurocognitive dysfunctions in temporal processes are crucial to the impulsiveness disorder of ADHD and provides first evidence for normalization with a dopamine reuptake inhibitor.

Author information

Author/s: Rubia, Katya (K); Halari, Rozmin (R); Christakou, Anastasia (A); Taylor, Eric (E);

Affiliation: Department of Child Psychiatry/MRC Center for Social, Genetic and Developmental Psychiatry (SGDP), Institute of Psychiatry, 16 De Crespigny Park, London, UK. k.rubia(-atsign-)iop.kcl.ac.uk

Grants: G9900839 (Agency:Medical Research Council) ; GO300155 (Agency:Medical Research Council)

Journal and publication information

Publication Type: Comparative Study; Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't

Journal: Philosophical transactions of the Royal Society of London. Series B, Biological sciences (Philos Trans R Soc Lond B Biol Sci), published in England. (Language: eng)

Reference: 2009-Jul; vol 364 (issue 1525) : pp 1919-31

Dates: Created 2009/06/02; Completed 2009/08/27;

PMID: 19487194, status: MEDLINE (last retrieval date: 8/27/2009, IMS Date: )

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