A meta-analysis found methylphenidate treatment of children with ADHD improves academic productivity more than accuracy, effecting performance in math more than reading.
Anne Fleur Kortekaas-Rijlaarsdam, MS
A new meta-analysis of more than 3 decades of research on methyphenidate (Ritalin, Novartis, others) treatment in children with attention-deficit/hyperactivity disorder (ADHD) found the medication improves academic productivity more than accuracy, and has greater effect on performance in math than reading or spelling.
The systematic review and meta-analysis by Anne Fleur Kortekaas-Rijlaarsdam, MS, Clinical Neuropsychopharmacology section, Vrije Universiteit Amsterdam, The Netherlands, and colleagues sought to characterize medication effects on academic performance which have not been previously established, including possible differential effects on specific academic subjects and whether previous measures of improvement (accuracy) were confounded by increased quantity attempted (productivity).
"It is thus important to distinguish between improvements in accuracy and productivity," the investigators indicate, "especially because long-term studies suggest that improvements in test scores with medication are often not accompanied by improvements in longer-term academic outcomes, such as grades and grade repetition."
Kortekaas-Rijlaarsdam suspects the disparity between short-term and long-term measures of academic performance is partly due to methylphenidate improving test-taking behaviors more than knowledge acquisition but does not rule out that long-term academic benefit can arise from a therapeutic effect on symptom and behavior.
"However, for these long-term outcomes, the use of randomized controlled trials (RCTs) is unethical, and, therefore, evidence (is) likely to be confounded by placebo-effects and poor medication adherence," she explained to MD Magazine. "As short-term effects of methylphenidate on classroom behaviors — including ADHD symptoms, on-task behavior and task productivity — found in RCT studies are robust, these improvements may, on the longer term, result in better academic outcomes."
Kortekaas-Rijlaarsdam and colleagues examined more than 2500 publication to identify 34 studies which met inclusion criteria, involving 1777 school age children. The studies were included for having valid study design, medication titration and dependent variables. In addition to distinguishing possible medication effects by academic subjects and differentiating between accuracy and productivity, this investigation added 6 years of literature to that scrutinized in previous meta-analysis.
The investigators reported that methylphenidate treatment of ADHD significantly improved math productivity by 7.8% and math accuracy by 3.0%. Although there was some increase in reading speed, there was no significant improvement in reading accuracy, and effects on spelling accuracy were inconclusive.
Several factors were examined as potential mediators or moderators of the medication effect on academic performance, including age, gender, ADHD-inattentive subtype, co-morbid obsessive-compulsive disorder or conduct disorder and parent and teacher-rated ADHD severity. Ultimately, none were found to statistically significantly interact with the medication effects.
"Taken together, our results do not support a mediating role for classroom-expressed ADHD symptoms in the relationship between methylphenidate and math accuracy, but this may be different for productivity measures, as behavioral improvements in the classroom are generally seen as a prerequisite for academic improvements, especially academic productivity," the investigators conclude.
Kortekaas-Rijlaarsdam emphasized to MD Magazine the main message for physicians is that the immediate effects of methylphenidate on academic performance are small and very specific. "Most improvement with this type of medication is seen on measures of academic effort/productivity," she said.
"It is therefore important to, when necessary, tone down the high expectations of parent and teachers about methylphenidate effects on academic performance," Kortekaas-Rijlaarsdam indicated. "The small magnitude of reported short- and long-term effects of methylphenidate efficacy suggests potential for other types of interventions. In line with current treatment guidelines, a previous meta-analysis showed more consistent improvement in academic performance with multimodal treatment compared to medication only."
The systematic review and meta-analysis of methylphenidate effect on academic performance of children with ADHD was published online January 20 in European Child & Adolescent Psychiatry.
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