Abstract
To examine the association between any breastfeeding duration and emotional and behavioral problems in 4-year-old children, considering psychosocial, demographic, and perinatal variables. The sample included 564 children. Any breastfeeding duration was categorized into four groups: no breastfeeding, 1-4 months, 4-8 months, and more than 8 months. Emotional and behavioral development was assessed using the Child Behavior Checklist 1(½)-5 (CBCL 1(½)-5). Multiple linear and logistic regression models were applied to explore associations between breastfeeding groups and CBCL 1(½)-5 outcomes. Any breastfeeding for 1-4 months was associated with lower scores on internalizing (β = - 4.21; p = 0.014) and externalizing (β = - 3.30; p = 0.044) problems scales, including emotional reactivity, anxiety/depression, somatic complaints, withdrawn behavior, and aggressiveness. It also reduced the risk of clinical scores for internalizing problems (OR = 0.035; p = 0.010) and symptoms compatible with autism spectrum disorder (ASD) (OR = 0.32; p = 0.041). Protective effects were found for 4-8 months of breastfeeding limited to specific subscales. No additional benefits were observed beyond 8 months. CONCLUSIONS: Early breastfeeding, particularly within the first 4 months, may protect effects against emotional and behavioral problems, suggesting that intensity rather than prolonged durations could be more relevant for child development. WHAT IS KNOWN: • Any breastfeeding has been associated with positive effects on child development, including possible protection against behavioral and emotional problems. • Evidence on the duration of any breastfeeding and its impact on mental health outcomes in early childhood remains inconsistent. WHAT IS NEW: • Breastfeeding during the first 4 months is associated with fewer internalizing and externalizing problems at 4 years. • Protective effects diminish beyond 8 months, suggesting intensity in the early period may be more relevant than prolonged duration.