Children whose mothers exclusively breastfeed them for at least six months may have a lower risk of developing attention-deficit hyperactivity disorder (ADHD), according to a new study published in the journal Biological Psychiatry. The findings suggest that prolonged breastfeeding could offer a protective effect against the condition.
ADHD is a neurodevelopmental disorder characterized by symptoms such as inattention, hyperactivity, and impulsivity, typically appearing before age 12. In the UK, the number of children diagnosed with ADHD has increased by a quarter since 2018, contributing to significant pressure on mental health services. Recent reports indicate that over one million children were referred to mental health services in England last year, and approximately 550,000 children and adults are currently awaiting NHS assessments for ADHD and related conditions.
Researchers from the University of Bergen in Norway analyzed data from over 37,000 mother-child pairs as part of the Norwegian Mother, Father and Child Cohort Study. They investigated the duration of exclusive breastfeeding and its association with ADHD symptoms observed at ages three, five, and eight years.
The study found that the longer a child was exclusively breastfed, up to six months, the lower the level of ADHD symptoms reported at these developmental stages. This protective association was observed in both boys and girls and was most pronounced at ages three and five. While all forms of breastfeeding showed a beneficial effect that increased with duration and intensity, the researchers concluded that exclusive breastfeeding for up to six months "could partially protect against childhood ADHD symptoms." They noted that further research is needed to confirm these results and to understand the specific mechanisms behind this protective effect, theorizing that breast milk may contain essential nutrients vital for brain development.
This study adds to a growing body of evidence highlighting the health benefits of breastfeeding. Previous research, including a major US review in 2025, has linked breastfeeding to reduced risks of infant mortality, rapid weight gain, infections, and allergies. However, some experts question the dramatic rise in ADHD diagnoses, suggesting that increased identification may reflect a "medicalization of distress" rather than a true increase in prevalence, where diagnosis becomes the primary means of accessing support.