Medication improves higher education entrance test scores of patients with ADHD
Higher education entrance examination scores are higher for patients with attention-deficit/hyperactivity disorder (ADHD) on medication compared with those who are not, a new cohort study has found.
“Among those with a diagnosis of ADHD, the use of ADHD medication was linked with higher scores in the [Swedish Scholastic Aptitude Test [(SweSAT)]; this result survived several sensitivity analyses,” researchers said. “These findings suggest that ADHD medications may help ameliorate educationally relevant outcomes in individuals with ADHD.”
A within-patient analysis of 930 individuals with ADHD (mean age 22.2±3.2 years) who took repeated SweSATs during their medicated and nonmedicated periods showed that the use of ADHD medications was significantly associated with higher SweSAT scores (mean difference [MD], 4.89; 95 percent CI, 2.26 to 7.34; p<0.001) after controlling for age and practice. [JAMA Psychiatry 2017;74:815-822]
The beneficial effect of ADHD medications was marginally higher in males (MD, 5.69; 2.14 to 9.23) than in females (MD, 3.60; 0.06 to 7.14; p=0.31 for difference).
“We adjusted for age and practice effects to address the confounding of increased test scores on repeated tests owing to the natural curve of improvement in ADHD symptoms and improvement in test taking ability,” explained researchers. [Psychol Med 2006;36:159-165]
“This finding suggests that the association between the use of ADHD medication and the test scores after controlling for age and practice effects is relatively robust. However, unmeasured confounders that vary within individuals might still be present,” they added.
The initial study population included 61,640 individuals with ADHD, of which only 6.0 percent (n=3,718) took the SweSAT during the study period. Majority (73.8 percent; n=2,745) received ADHD medication and, compared with those who had never been medicated, earned significantly higher mean test scores (p<0.001).
The main study outcome was the score on the SweSAT, and the study follow-up period included 16 testing occasions. A conditional generalized estimating equation was used to compare SweSAT scores of the same patient during medicated and nonmedicated periods.
Notably, the proportion of SweSAT takers was around three times higher in the population controls than in the ADHD patients, while the IQ values were comparable between the two groups. Moreover, participants were further restricted to those who had taken multiple tests. All of these contribute to a high potential of self-selection that the study failed to control for, the researchers said.
Regardless, the study was able to show that medication exerts statistically significant improvements on the SweSAT scores of individuals with ADHD. Importantly, these findings may likely be reflected in other countries with similar testing systems.
“Because higher education entrance examinations comparable to the SweSAT exist in most countries, our results of a positive association between medication use and these tests in individuals with ADHD may be generalizable to countries with a similar prevalence of ADHD medication use,” they said.