Does methylphenidate improve academic performance? A systematic review and meta-analysis.

Academic improvement is amongst the most common treatment targets when prescribing stimulants to children with ADHD. Previous reviews on stimulant-related academic improvements are inconclusive and focus on task engagement. Recent literature suggests outcome-domain-specific medication effects that are larger for productivity than for accuracy. The aims of this study are quantifying methylphenidate effects on academic productivity and accuracy for math, reading, spelling; exploring the mediating or moderating effects of symptom improvements, demographic-, design- and disorder-related variables. PubMed, EMBASE, ERIC and PsycINFO were searched for articles reporting methylphenidate effects on academic productivity and accuracy. Thirty-four studies met entry criteria. Methylphenidate improved math productivity (7.8% increase, p < .001); math accuracy (3.0% increase, p = .001); increased reading speed (SMD .47, p < .001) but not reading accuracy. None of the mediators or moderators tested affected methylphenidate efficacy. Academic improvements were small compared to symptom improvements; qualitative changes limited to math. Clinicians should take this discrepancy into account when prescribing medication for ADHD.

Short-Term Effects of Methylphenidate on Math Productivity in Children With Attention-Deficit/Hyperactivity Disorder are Mediated by Symptom Improvements: Evidence From a Placebo-Controlled Trial.

BACKGROUND: Although numerous studies report positive effects of methylphenidate on academic performance, the mechanism behind these improvements remains unclear. This study investigates the effects of methylphenidate on academic performance in children with attention-deficit/hyperactivity disorder (ADHD) and the mediating and moderating influence of ADHD severity, academic performance, and ADHD symptom improvement. METHODS: Sixty-three children with ADHD participated in a double-blind placebo-controlled crossover study comparing the effects of long-acting methylphenidate and placebo. Dependent variables were math, reading, and spelling performance. The ADHD group performance was compared with a group of 67 typically developing children. RESULTS: Methylphenidate improved math productivity and accuracy in children with ADHD. The effect of methylphenidate on math productivity was partly explained by parent-rated symptom improvement, with greater efficacy for children showing more symptom improvement. Further, children showing below-average math performance while on placebo profited more from methylphenidate than children showing above-average math performance. CONCLUSIONS: The results from this study indicate positive effects of methylphenidate on academic performance, although these were limited to math abilities. In light of these results, expectations of parents, teachers, and treating physicians about the immediate effects of methylphenidate on academic improvement should be tempered. Moreover, our results implicate that positive effects of methylphenidate on math performance are in part due directly to effects on math ability and in part due to reductions in ADHD symptoms.

Methylphenidate-Related Improvements in Math Performance Cannot Be Explained by Better Cognitive Functioning or Higher Academic Motivation: Evidence From a Randomized Controlled Trial.

Objective: 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. Method: Sixty-three children (ADHD diagnosis; methylphenidate treatment; age 8-13; IQ > 70) were randomly allocated to a 7-day methylphenidate or placebo treatment in this double-blind placebo-controlled crossover study and compared with 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) or 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.