Anne Fleur Kortekaas-Rijlaarsdam

CHAPTER 4 78 ABS T RAC T Objectives This study investigated whether improvements in working memory, reaction time, lapses of attention, interference control, academic motivation and perceived competence mediated effects of methylphenidate on math performance. Methods Sixty-three children (ADHD diagnosis; methylphenidate treatment; age 8-13; IQ>70) were randomly allocated to 7-day methylphenidate- or placebo-treatment in this double-blind placebo-controlled crossover study; compared to 67 controls. Data were collected at schools and analyzed using mixed-model analysis. Methylphenidate was hypothesized to improve all measures; all measures were evaluated as potential mediators of methylphenidate-related math improvements. Results Controls mostly outperformed the ADHD-group. Methylphenidate did not affect measures of cognitive functioning ( p =.082-.641), nor academic motivation ( p =.199- .865). Methylphenidate improved parent-ratings of their child’s self-perceived competence ( p <.01), which mediated methylphenidate-efficacy on math productivity. Conclusion These results question the necessity of improvements in specific cognitive and motivational deficits associated with ADHD for medication-related academic improvement. They also stimulate further study of perceived competence as a mediator.