ADHD Severity, Diagnosis, and Later Academic Achievement in a Nationally Representative Sample
*Names in bold indicate Presenter
Methods: We use the nationally representative Early Childhood Longitudinal Study-Kindergarten Cohort (ECLS-K) sample of 7,840 U.S. kindergartners in 1998 followed through eighth grade. Parents and teachers reported all children’s inattention, hyperactivity/impulsivity, and oppositional-defiance. We isolated the association between reported diagnosis (N=350 children (4.5%) ages 4-9) and eighth grade academic achievement by comparing diagnosed to undiagnosed children reported to have the same inattentive-hyperactive and oppositional-defiant behaviors, baseline achievement, health, and demographics. Stratified regression analysis isolated the diagnosis-achievement relationship for mild, moderate, and severe behavior without and with treatments.
Results: ADHD diagnosis was associated with -0.30 SD (95% confidence interval [CI]: -0.44, 0.17) lower achievement among children with mild ADHD behaviors and -0.08 SD (95% CI: -0.26, 0.10) lower achievement among children with severe ADHD behaviors, ceteris paribus. Pharmacological treatment and behavioral services entirely counteracted the negative effects of diagnosis among children with severe ADHD, but offset only 2/3 of the estimated effect among children with mild ADHD.
Conclusions: Negative factors associated with an ADHD diagnosis outweighed potential benefits for academic achievement among children with mild ADHD behaviors, even those treated pharmacologically and behaviorally. By contrast, an ADHD diagnosis and treatment was neutral to beneficial for children with moderate-to-severe ADHD behaviors.