The large Multimodal Treatment Study of Children with adhd (mta) has become widely known especially because in the treatment phase intensive medication management appeared to be superior (on some outcome-measures) to other treatment modalities. The second followup, 22 months after the end of the treatment phase, shows several surprising and controversial results. For example, the advantage of having partaken in the intensive medication algorithm has disappeared and continued stimulant treatment is a marker not of beneficial outcome, but of deterioration (higher symptom scores). The balance of advantages and disadvantages of longterm stimulant treatment appears to be considerably less favourable than previously thought. A reconsideration of several widely held views on stimulant treatment would seem in order. However, in The Netherlands the results of the second follow-up do not seem to draw the amount of attention and publicity the previous findings did. A possible reason for this is that they contradict prevailing ideas on adhd. The goal of this article is to draw attention to the most important findings and clinical implications of the second follow-up. At the same time the article illustrates the extent to which the dissemination of scientific knowledge is a social process.