Anne Fleur Kortekaas-Rijlaarsdam

79 MPH EFFECTS ON MATH PERFORMANCE: INFLUENCE OF COGNITION, MOTIVATION AND PERCEIVED COMPETENCE 4 I N T RODUC T I ON Attention-Deficit Hyperactivity Disorder (ADHD) is a developmental disorder characterized by attentional problems, hyperactivity and impulsivity (American Psychiatric Association, 2013). Children with ADHD often experience problems at school, varying from mild underperformance to the need for special education or school drop-out (G. J. DuPaul, 2007). Academic underperformance is one of the main reasons for referral for treatment with stimulant medication being the most commonly prescribed treatment (Wright et al., 2015). Although behavioral improvements of stimulant medication are robust (MTA-group, 1999b; Van der Oord et al., 2008), effects on academic performance are often limited to mathematical performance and improvements in quality (accuracy) are generally smaller than improvements in productivity (e.g. Benedetto-Nasho & Tannock, 1999; Froehlich et al., 2014; McGough et al., 2006; Murray et al., 2011). Effect sizes are small and improvements in schoolwork quality are less evident. Moreover, evidence for long term improvement of academic performance is lacking so far (Arnold, Hodgkins, Kahle, Madhoo, & Kewley, 2015; Baweja, Mattison, &Waxmonsky, 2015; Froehlich et al., 2014; Kortekaas-Rijlaarsdam, Luman, Sonuga-Barke, Bet, & Oosterlaan, 2017b; Langberg & Becker, 2012; Prasad et al., 2013). In addition to ADHD symptoms, cognitive and motivational problems may further contribute to academic underperformance in children with ADHD ( Luman et al., 2005; Willcutt et al., 2005). Cognitive problems of children with ADHD are especially apparent in attention, working memory and response inhibition, all functions where deficits have previously shown to be associated with academic underperformance (Joseph Biederman et al., 2004; Mayes & Calhoun, 2007b; Preston et al., 2009; Thorell, 2007). Given the robust evidence for these specific cognitive deficits in children with ADHD and the association of such deficits with academic underperformance, these deficits might also contribute to the academic problems of these children (Mullane, Corkum, Klein, & McLaughlin, 2009b; Willcutt et al., 2005). Several studies suggest that low academic motivation also contributes to the academic underperformance of children with ADHD (DuPaul et al., 2004; Langberg, Arnold, Hinshaw, & Swanson, 2012). For example, self-rated intrinsic academic motivation is lower for children with ADHD than for typically developing (TD) children. These motivational problems are also confirmed by lower parent- and teacher-ratings of these children’s academic motivation (Carlson et al., 2002). This lower intrinsic academic motivation is likely to negatively influence school performance for children with