Anne Fleur Kortekaas-Rijlaarsdam

37 MPH AND ACADEMIC PERFORMANCE: META-ANALYSIS 2 D I SCUSS I ON The current meta-analysis and systematic review summarized more than three decades of research on the effects of MPH on academic performance in ADHD. Our analysis particularly focused on the question whether MPH improves academic accuracy or just academic productivity. There were small to medium sized, positive effects of MPH on math accuracy, math productivity and reading accuracy. Math accuracy increased by 3.0%, whereas math productivity increased by 7.8%. MPH did not improve reading accuracy, but did improve the number of items attempted in reading (medium effect). Results from our qualitative synthesis regarding math performance corroborated the findings from our meta-analyses. The qualitative synthesis of the studies reporting on spelling accuracy was inconclusive and more studies on this topic are needed. Our main results underline the importance of assessing a full range of outcome measures (accuracy and productivity) and different academic subjects when studying the effects of MPH on academic performance. Moreover, these results underline the contrast between the large symptom improvements obtained with MPH and the small to medium sized improvements in school performance – with improvements are restricted to certain academic subjects, and are small or absent for measures of accuracy. However, it is important to realize that the short-term tests of academic performance used in the studies analyzed, are sensitive to potential longer-term benefits of MPH. Thus, it may be that although positive effects of MPH on academic accuracy are small or absent on the short term, MPH-related behavioral improvements and increased productivity may result in long term better school performance. Currently, evidence for long term effects of MPH on academic performance is lacking (Langberg & Becker, 2012) but cannot be ruled out because of methodological issues (i.e. the lack of long term RCTs). Figure 2.5 Forest plot of the effects of MPH on reading number attempted