Aim: The relation of longer duration of breast-feeding to cognitive development was been demonstrated in several previous studies, however its potential impact on behaviour is unknown. We assess which behavioural areas (executive function, social competence, attention behaviour and hyperactivity) are related to long-term breast-feeding in young children.
Methods: Two prospective population-based birth cohorts, one from the island of Menorca (N = 421) and the second from Ribera d'Ebre county (N = 79) in Spain were followed up at the age of 4 years during a two year period (2001-2003). Children were assessed by three psychologists and their respective teachers for neuropsychological functions (McCarthy test), attention-hyperactivity behaviours (Attention-Deficit Hyperactivity Disorder Criteria of DSM-IV) and social behaviour (California Preschool Social Competence Scale).
Results: Long-term breast-feeding was associated with executive function scores (an increase of 4.9 points after breast-feeding >20 weeks), and the improvement of social competence scores (relative risk for being in the poorest 20%, RR = 0.57; 0.52-0.66, after >12 weeks) and attention-deficit hyperactivity symptom scores (RR = 0.56; 0.37-0.85, after >12 weeks). All three outcomes remained significant when included as covariates in the regression models.
Conclusion: Long-term breast-feeding was found to be associated with fewer attention and hyperactivity symptoms and an improvement in related behavioural areas (neuropsychological and socio-behavioural outcomes).