Conflict of interest statement: Dr David Coghill is an advisory board member for Eli Lilly, Janssen Cilag, Shire, Cephalon and UCB and has research funding from Eli Lilly and Janssen Cilag. Prof. Keith Matthews and Dr Sinead Rhodes have nothing to disclose.
Acute neuropsychological effects of methylphenidate in stimulant drug-naïve boys with ADHD II – broader executive and non-executive domains
Article first published online: 9 JUN 2006
Journal of Child Psychology and Psychiatry
Volume 47, Issue 11, pages 1184–1194, November 2006
How to Cite
Rhodes, S. M., Coghill, D. R. and Matthews, K. (2006), Acute neuropsychological effects of methylphenidate in stimulant drug-naïve boys with ADHD II – broader executive and non-executive domains. Journal of Child Psychology and Psychiatry, 47: 1184–1194. doi: 10.1111/j.1469-7610.2006.01633.x
- Issue published online: 9 JUN 2006
- Article first published online: 9 JUN 2006
- Manuscript accepted 1 February 2006
- executive functioning;
Background: Accumulating evidence supports methylphenidate-induced enhancement of neuropsychological functioning in attention deficit hyperactivity disorder (ADHD). The present study was designed to investigate the acute effects of the psychostimulant drug, methylphenidate (MPH), on neuropsychological performance in stimulant naïve boys with ADHD.
Methods: Seventy-three drug-naïve boys (age 7–15) with ADHD (combined type) completed neuropsychological tasks from the CANTAB battery under randomised, placebo controlled, double-blind conditions following an acute challenge with either placebo (n = 24), .3 (n = 25) or .6 (n = 24) mg/kg oral MPH.
Results: MPH did not impair performance on any task. MPH (.6 mg/kg) lengthened response latencies on a task of Spatial Recognition, shortened response times on a Reaction Time task and restored performance on a Delayed Matching to Sample visual, non-working memory task. Contrary to predictions, MPH did not enhance performance on tasks with a prominent executive component, including Go/NoGo, Spatial Working Memory, Stockings of Cambridge and Attentional Set shifting tasks.
Conclusions: Acute administration of MPH to drug-naïve boys with ADHD did not impair neuropsychological performance. Acute MPH enhanced performance on some aspects of non-executive functioning. MPH-induced slowing of responding on a relatively complex Spatial Recognition memory task and quickened responding on a reaction time task requiring less cognitive resources suggests that MPH may act by improving self-regulatory ability. MPH may not exert its effects on neuropsychological functioning by enhancing executive processes.