Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/12892
Appears in Collections:Management, Work and Organisation Journal Articles
Peer Review Status: Refereed
Title: Dissociation in response to methylphenidate on response variability in a group of medication naive children with ADHD
Authors: Johnson, Katherine A
Barry, Edwina
Bellgrove, Mark A
Cox, Marie
Kelly, Simon P
Daibhis, Aoife
Daly, Michael
Keavey, Michelle
Watchorn, Amy
Fitzgerald, Michael
McNicholas, Fiona
Kirley, Aiveen
Robertson, Ian H
Gill, Michael
Contact Email: michael.daly@stir.ac.uk
Keywords: response time
methylphenidate
variability
dopamine
ADHD
Issue Date: 2008
Publisher: Elsevier
Citation: Johnson KA, Barry E, Bellgrove MA, Cox M, Kelly SP, Daibhis A, Daly M, Keavey M, Watchorn A, Fitzgerald M, McNicholas F, Kirley A, Robertson IH & Gill M (2008) Dissociation in response to methylphenidate on response variability in a group of medication naive children with ADHD, Neuropsychologia, 46 (5), pp. 1532-1541.
Abstract: Increased variability in reaction time (RT) has been proposed as a cardinal feature of attention deficit hyperactivity disorder (ADHD). Increased variability during sustained attention tasks may reflect inefficient fronto-striatal and fronto-parietal circuitry; activity within these circuits is modulated by the catecholamines. A disruption to dopamine signaling is suggested in ADHD that may be ameliorated by methylphenidate (MPH). This study investigated the effects of MPH administration on the variability in RT and error performance on a sustained attention task of a group of 31 medication naïve children with ADHD, compared with 22 non-ADHD, non-medicated, control children. All children performed the fixed-sequence sustained attention to response task (SART) at two time-points: at baseline and after six weeks. The children with ADHD were tested when medication naive at baseline and after six weeks of treatment with MPH and whilst on medication. The medication naïve children with ADHD performed the SART with greater errors of commission and omission when compared with the control group. They demonstrated greater standard deviation of RT and fast moment-to-moment variability. They did not differ significantly from the control group in terms of slow variability in RT. MPH administration resulted in reduced and normalised levels of commission errors and fast, moment-to-moment variability in RT. MPH did not affect the rate of omission errors, standard deviation of RT or slow frequency variability in RT. MPH administration may have a specific effect on those performance components that reflect sustained attention and top-down control rather than arousal.
Type: Journal Article
URI: http://hdl.handle.net/1893/12892
DOI Link: http://dx.doi.org/10.1016/j.neuropsychologia.2008.01.002
Rights: The publisher does not allow this work to be made publicly available in this Repository. Please use the Request a Copy feature at the foot of the Repository record to request a copy directly from the author. You can only request a copy if you wish to use this work for your own research or private study.
Affiliation: Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin
Nathan S. Kline Institute, New York
Trinity College, Dublin
Socio-Management
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin
Our Lady's Hospital for Sick Children, Dublin
Trinity College, Dublin
Trinity College, Dublin
Trinity College, Dublin

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