ADHD and Student Grades in Children from the ABCD Study®: A Twin and Siblings Study

2026/07/24 by Luís Fernando Silva Castro-de-Araujo, Luis F. S. Castro-de-Araujo, Daniel Zhou +5
Medicine · Neuroscience · #Attention Deficit Hyperactivity Disorder #Functional Brain Connectivity Studies #Autism Spectrum Disorder Research

paper · pdf · doi:10.1007/s10519-026-10274-0

Abstract

Abstract Attention-deficit/hyperactivity disorder (ADHD) symptoms are strongly associated with lower academic performance, yet the nature of this association remains uncertain. We analyzed data from twins and siblings in the Adolescent Brain Cognitive Development (ABCD) Study ® to examine the relationship between ADHD symptoms and school grades using genetically informed models. ADHD symptoms were assessed via the Child Behavior Checklist, and grades were caregiver-reported for the previous school year. Both phenotypes were modeled as ordinal variables. We applied Direction of Causation (DoC) and Mendelian randomization extensions (MR-DoC and MR-DoC2) incorporating polygenic risk scores for ADHD and educational attainment. DoC and MR-DoC comparisons did not distinguish directionality (e.g., DoC forward path estimate = − 0.16, 95% CI [− 0.26, − 0.07]; reverse path = − 0.30, 95% CI [− 0.63, − 0.17]). In MR-DoC2, estimates differed in precision: ADHD-to-grades path = − 0.31, 95% CI [− 0.62, − 0.11]; grades-to-ADHD path = − 0.60, 95% CI [− 1.20, 0.03]. Sex-limitation tests indicated no moderation by sex.

Citations

• Direction of Causation Modeling Between Cross-Sectional Measures of Parenting and Psychological Distress in Female Twins
• Sex differences in genetic and environmental influences on DSM–III–R attention-deficit/hyperactivity disorder.
• PLINK: A Tool Set for Whole-Genome Association and Population-Based Linkage Analyses
• Testing hypotheses about direction of causation using cross-sectional family data
• A test of the equal-environment assumption in twin studies of psychiatric illness
• Model-free Estimation of Recent Genetic Relatedness
• Familial aggregation of attention‐deficit/hyperactivity disorder
• Attention Deficit Hyperactivity Disorder Symptoms and Low Educational Achievement: Evidence Supporting A Causal Hypothesis
• Extending Causality Tests with Genetic Instruments: An Integration of Mendelian Randomization with the Classical Twin Design
• The Analytic Identification of Variance Component Models Common to Behavior Genetics
• MR-DoC2: Bidirectional Causal Modeling with Instrumental Variables and Data from Relatives
• Genetic and Environmental Variation in Continuous Phenotypes in the ABCD Study®
• Measurement Error and Power in Family-Based Extensions to Mendelian Randomization

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