Genetic heterogeneity due to racial/ethnic background and stimulant treatment for ADHD during development could have had an influence on the main results of the study. Therefore, to empirically garner information on this possibility, the developmental change models were re-analyzed with race/ethnicity and number of years an individual had been treated for ADHD with stimulant medication (ranging from no lifetime use to 12 years of treatment) included as covariates. The results of these secondary analyses are provided in Supplementary Tables S4 and S5. As can be seen in the tables, no appreciable changes in the results were detected. Thus, the sensitivity of the primary findings appears to be conserved in light of the potential influence of genetic heterogeneity and treatment history.
