According to the US Drug Enforcement Administration the production of MPH in the US increased nearly six-fold from 1990 to 1995. Whether or not this huge increase accurately reflected the expansion of MPH treatment was a matter of debate in the 1990s. According to Safer et al. there occurred a 2.5fold increase in the prevalence of MPH treatment of youths with ADHD from 1990 to 1995. This estimate was less alarming than a previous one. Moreover, Mechlorethamine hydrochloride Safer’s data have been questioned by a subsequent study. However, Safer and colleagues used another approach to confirm their original estimate and three studies by two independent groups also reported estimates consistent with Safer’s study. In 1999 Biederman et al. published a study showing that pharmacotherapy of ADHD reduces the risk for later development of substance use disorder. In 2003 the same group published a meta-analysis supporting the same conclusion although with a smaller effect size. This meta-analysis included several studies that were not published in peer-reviewed journals and three studies reporting either an enhanced SUD risk, a protective effect or no effect. Subsequent studies either reported a protective effect or no effect. The During the 1990s, press coverage of scientific studies about the biology and etiology of ADHD contributed “to much wider acceptance of the disorder as having neurological and genetic, rather than environmental origins”. Newspaper articles reporting on our “top 10” publications repeatedly claimed that these findings might soon result in improved pharmacological treatments and in commercially available biomarkers to confirm the ADHD diagnosis. None of these promises have yet been fulfilled. Moreover, general agreement now exists among scientists that environmental risk factors play a central role in ADHD etiology. Because newspapers failed to inform the lay public that most initial scientific claims were later refuted or strongly attenuated, they did not reflect the evolution of scientific knowledge. In turn, because scientific findings echoed by newspapers are more 
often cited in the scientific literature, this biased media coverage probably favors the visibility of initial findings. Therefore, not only the lay public but also a substantial proportion of interested professionals, scientists and clinicians might be influenced by this inaccurate media coverage. This might have detrimental consequences on the management and prevention of ADHD. We showed here, using the example of ADHD, that press coverage of health issues, by strongly favoring initial studies, ignores the publication bias resulting from the devaluation trends of initial findings. If further investigations of other health issues confirm our observations and reinforce our interpretations, it might be timely for scientists, journal editors and university media writers to define and respect ethical rules regarding health science communication. For example, press releases reporting on an initial study should include a warning statement pointing out that these findings must be confirmed by subsequent independent investigations. Indeed, the quality of press releases positively influences the quality of associated newspaper stories. The time would be also right to warn journalists about this major publication bias inherent to the scientific process.conclusion of one publication has been questioned by one previous and one subsequent publication and confirmed by four others. Pimozide Finally, one publication has been fully confirmed by a meta-analysis and not questioned subsequently. Because we only focused on ADHD, generalization of our observations to other biomedical domains remains hypothetical. However, the hypothesis that grounded our study originated from the seminal studies by Ioannidis and coworkers.