RETRACTED: Effects of methylphenidate on the fixed-ratio performance of mentally retarded children.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief based on the outcome of a report conducted by the National Institute of Mental Health (NIMH) in 1987 that was recently brought to the attention of the journal by R.T. Warne. Based on allegations of scientific fraud against Stephen Breuning, the NIMH conducted a full investigation into the alleged scientific misconducted on two grants, which funded multiple publications, one of which was this article. The NIMH report concluded that “all of these review publications relied heavily on Dr. Breuning's own work which the Panel concluded was not carried out as reported. The publications, therefore, must be regarded as scientifically unsound and seriously misleading.” Pharmacology, Biochemistry and Behaviour are therefore retracting this article on the grounds of scientifically unsound and misleading data and conclusions. The full NIMH investigatory report can be located here: NIMH-Breuning-Investigation-final-report.pdf (kindly provided by R.T. Warne)