doi:10.1017/S1047951111000928, Published by Cambridge University Press, 19 July 2011.
The paper is listed as being on behalf of the European Network for Hyperactivity Disorders and the Association of European Paediatric Cardiology. This second attribution ‘Association of European Paediatric Cardiology’ was deleted from the text, and should have been deleted from the author list. The author apologises for this error.