Association between infant feeding and ADHD development in childhood: a birth cohort study in Taiwan

Abstract

Background: Infant feeding plays a vital role in neurodevelopment, and a lack of breastfeeding and complementary feeding may increase the risk of developing attention-deficit/hyperactivity disorder (ADHD). However, empirical evidence on this relationship remains uncertain, as most studies are based on cross-sectional designs. Therefore, this study aimed to examine this temporal relationship using longitudinal data from a birth cohort. Methods: A retrospective cohort study was conducted using data from Wave I (starting at 6 months old, 2005–2006) to Wave IV (up to 5 years old, 2010–2011) of the Taiwan Birth Cohort Study. A total of 19,721 pairs completed the four-wave interviews and provided information on infant feeding, medical history, ADHD occurrence, and sociodemographic characteristics. An extended Cox model with time-dependent covariates was used to examine this association. Results: In total, 207 infants developed ADHD during the 54-month observational period, with an estimated cumulative incidence of 5.56 per 1,000 person-years. The average breastfeeding duration was approximately 2 months. With complementary feeding, rice solid food (HR = 0.73) was found to be a protective factor against developing ADHD. Significantly associated factors for increasing ADHD risk included males, lower family income, low birth weight, maternal weight, advanced maternal age, child gastrointestinal disease, child seizures, maternal heart disease, and paternal diabetes mellitus. Conclusions: Complementary feeding within 6 months is important to protect infants from developing ADHD. The beneficial effect of breastfeeding within 6 months was not observed while controlling for other risk factors. However, owing to the limitation of a smaller number of ADHD cases, further studies should rely on larger observational periods.