Breastfeeding has been associated with a lower risk of attention-deficit/hyperactivity disorder (ADHD). However, most studies examining this association have focused on small samples outside the United States or were likely subject to substantial residual confounding. Our objectives were to investigate, in a nationally representative sample of preschool children in the United States, the associations between ADHD and both age of breastfeeding cessation and age of formula introduction, as well as associations between ADHD and exclusive breastfeeding duration.
Analysis of data from children aged 3 to 5 years in the 2011/12 National Survey of Children's Health (n = 12,793). Logistic regressions were used to model current medical diagnosis of preschool ADHD as a function of breastfeeding duration, breastfeeding exclusivity, and the timing of formula introduction with adjustment for 12 potential confounders using propensity scores, including sex, age, race, household income, prematurity, insurance, and medical home.
After adjustment for potential confounders, exclusive breastfeeding for at least 6 months was associated with substantially reduced odds of ADHD (adjusted prevalence odds ratio [aPOR] = 0.38; 95% confidence interval [CI], 0.15–0.99). Breastfeeding duration was also associated with ADHD, with 8% reduced odds of ADHD for each additional month of breastfeeding (aPOR = 0.92; 95% CI, 0.86–0.99). The results for exclusive breastfeeding duration were similar, but the confidence interval included the null (aPOR = 0.92; 95% CI, 0.85–1.00). The age of formula introduction was not associated with ADHD (aPOR = 0.92; 95% CI, 0.81–1.05).
In a nationally representative sample of preschool children, breastfeeding was associated with a lower prevalence of ADHD. These findings provide evidence in support of the neurodevelopmental benefits of breastfeeding.