Children's Attention-Deficit/Hyperactivity Disorder Symptoms Predict Lower Diet Quality but Not Vice Versa: Results from Bidirectional Analyses in a Population-Based Cohort

Background: As an adjuvant for medication, dietary changes focused on specific nutrients have been proposed to prevent or reduce attention-deficit/hyperactivity disorder (ADHD) symptoms. However, whether an overall healthy dietary pattern is associated with ADHD symptom severity during childhood remains unclear. Furthermore, it is not clear what the direction of this association is. Objectives: We aimed to examine the association between dietary patterns and ADHD symptoms in school-aged children. In addition, we aimed to identify the temporal direction of this association-that is, whether dietary patterns predict ADHD symptoms or vice versa. Methods: We analyzed data from 3680 children participating in the Generation R Study, a prospective cohort in Rotterdam, Netherlands. ADHD symptoms were assessed with parent-report questionnaires at ages 6 and 10 y using the Child Behavior Checklist. Dietary intake was assessed at the age of 8 y with a validated food-frequency questionnaire. We computed a diet quality score reflecting adherence to dietary guidelines. We examined bidirectional associations of diet quality with ADHD symptom scores using multivariable linear regression analysis and cross-lagged modeling. Results: Linear regressions showed that more ADHD symptoms at age 6 y were associated with a lower diet quality score at age 8 y (SD score = -0.08; 95% CI: -0.11, -0.05) but that diet quality at age 8 y was not associated with ADHD symptoms at age 10 y. Cross-lagged models confirmed a unidirectional relation from ADHD symptoms to diet quality but not vice versa. Associations did not differ by overweight status or between boys and girls. Conclusion: Our study suggests that children with more ADHD symptoms may be at higher risk of an unhealthy diet but that overall diet quality does not affect ADHD risk.