TOPLINE:

Early breastfeeding, particularly during the first 4 months of life, was associated with fewer emotional and behavioural problems in children at the age of 4 years. Children breastfed for this duration had reduced internalising and externalising problems, aggressive behaviour, and symptoms related to autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). No additional benefit was observed beyond 8 months of breastfeeding.

METHODOLOGY:

• Researchers analysed 564 children aged 4 years from two Spanish cohorts (between 2013 and 2021, n = 289 and between 2014 and 2019, n = 275) to evaluate the association between the duration of breastfeeding and emotional and behavioural outcomes.
• Parent-reported breastfeeding duration was categorised into four groups as no breastfeeding, 1-4 months, 4-8 months, and more than 8 months.
• Emotional and behavioural outcomes were measured using the Child Behavior Checklist for Ages 1.5-5 years, including syndrome scales (emotional reactivity, withdrawn behaviour, anxiety/depression, somatic complaints, and aggressiveness), broad-band scales (internalising, externalising, and total problems), and Diagnostic and Statistical Manual of Mental Disorders-oriented scales (ASD and ADHD).

TAKEAWAY:

• After adjustments, breastfeeding for 1-4 months was associated with lower scores for internalising problems (beta-coefficient [β], -4.21), externalising problems (β, -3.30), and total problems (β, -4.13; P < .05 for all) than no breastfeeding.
• Any breastfeeding during the first 4 months was associated with lower scores for emotional reactivity, anxiety/depression, somatic complaints, withdrawn behaviour, aggressiveness, and symptoms for ASD and ADHD (P < .05 for all).
• Children breastfed for 1-4 months had 65% lower odds of internalising problems (odds ratio [OR], 0.35) and 68% lower odds of ASD (OR, 0.32; P < .05 for both) than non-breastfed children.
• Breastfeeding for 4-8 months was associated with 75% lower odds of withdrawn behaviour (OR, 0.25; P = .022); however, breastfeeding beyond 8 months showed no additional benefits for emotional or behavioural outcomes.

IN PRACTICE:

"Rather than considering breastfeeding as an isolated determinant, it should be understood as part of a broader biopsychosocial network that includes parental emotional health, caregiving practices, early attachment, and family environment," the authors wrote. "These findings reinforce the importance of promoting breastfeeding as a strategy not only for nutritional benefits but also for supporting early emotional development and mental health," they added.

SOURCE:

This study was led by Vargas-Pérez Susana and Hernández-Martínez Carmen, Rovira i Virgili University, Tarragona, Spain. It was published online on December 24, 2025, in the European Journal of Pediatrics.

LIMITATIONS:

The intensity of breastfeeding could not be evaluated because the feeding frequency and breastfeeding type were not measured. Retrospective parent reports of breastfeeding and outcomes may have introduced shared informant bias. Cohort attrition and differences between the two study populations may have limited generalisability.

DISCLOSURES:

Open access funding was provided by the CRUE-CSIC agreement with Springer Nature. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.