Conflict of interest statement: Dr Jain sits on the Advisory Boards of Biovail, Wyeth, Purdue, Eli Lilly, Shire, and Janssen-Ortho, has sponsorships from Wyeth, Purdue, Eli Lilly, Shire, Janssen-Ortho, and Novartis, and does research for Purdue, Eli Lilly, and Janssen-Ortho. Neither he nor his family has financial interests in these companies. Dr Tannock receives research funds from Eli Lilly, Shire, and Novartis, sits on the Advisory Boards of Eli Lilly and Pfizer, acts as a consultant to Eli Lilly, is a member of the Speaker's Bureau of Eli Lilly and McNeil, and receives honoraria from Eli Lilly, Shire, Janssen-Ortho, McNeil, and Pfizer.
Effects of methylphenidate on working memory components: influence of measurement
Article first published online: 5 JUN 2007
Journal of Child Psychology and Psychiatry
Volume 48, Issue 9, pages 872–880, September 2007
How to Cite
Bedard, A.-C., Jain, U., Johnson, S. H. and Tannock, R. (2007), Effects of methylphenidate on working memory components: influence of measurement. Journal of Child Psychology and Psychiatry, 48: 872–880. doi: 10.1111/j.1469-7610.2007.01760.x
- Issue published online: 9 AUG 2007
- Article first published online: 5 JUN 2007
- Manuscript accepted 12 February 2007
- Attention-deficit hyperactivity disorder;
- working memory;
- clinical trial.
Background: To investigate the effects of methylphenidate (MPH) on components of working memory (WM) in attention-deficit hyperactivity disorder (ADHD) and determine the responsiveness of WM measures to MPH.
Methods: Participants were a clinical sample of 50 children and adolescents with ADHD, aged 6 to 16 years old, who participated in an acute randomized, double-blind, placebo-controlled, crossover trial with single challenges of three MPH doses. Four components of WM were investigated, which varied in processing demands (storage versus manipulation of information) and modality (auditory-verbal; visual-spatial), each of which was indexed by a minimum of two separate measures.
Results: MPH improved the ability to store visual-spatial information irrespective of instrument used, but had no effects on the storage of auditory-verbal information. By contrast, MPH enhanced the ability to manipulate both auditory-verbal and visual-spatial information, although effects were instrument specific in both cases.
Conclusions: MPH effects on WM are selective: they vary as a function of WM component and measurement.