A large-scale study from the University of Bergen has found that children who are exclusively breastfed for the first six months of life show fewer symptoms of attention deficit hyperactivity disorder (ADHD) later in childhood. The research, which tracked more than 37,000 children born in Norway between 1999 and 2009, adds to a growing body of evidence linking early nutrition to neurodevelopmental outcomes.
Berit Skretting Solberg, a psychiatrist and researcher at the Department of Biomedicine at the University of Bergen and senior consultant at Betanien Hospital, led the analysis. “We found that the longer a child was exclusively breastfed (up to six months), the lower the level of ADHD symptoms at ages three, five, and eight years,” Solberg said. She noted that while heredity remains the strongest known risk factor for ADHD, environmental and dietary factors also play a role.
Sex Differences and Duration Effects
The study revealed notable differences between boys and girls. Girls showed the strongest associations between exclusive breastfeeding and reduced ADHD symptoms at all measured ages. The researchers suggest that biological mechanisms—such as the composition of breast milk—may interact differently with male and female neurodevelopment.
Any breastfeeding was linked to lower ADHD symptoms, but the effect increased with both duration and intensity. Exclusive breastfeeding for the full six months produced the most pronounced benefits. The average duration of exclusive breastfeeding among participants was under four months, indicating that many mothers stop earlier than recommended.
ADHD is a behavioural and neurodevelopmental condition characterised by inattention, hyperactivity, and impulsivity. It is typically diagnosed in childhood and has no cure, though behavioural therapy and medication can help manage symptoms. The findings from Bergen align with broader European public health guidance: the World Health Organization and UNICEF recommend exclusive breastfeeding for the first six months of life, meaning no other foods or liquids—including water—are given.
Biological Plausibility
The researchers point to several biological pathways that could explain the link. Breast milk contains macronutrients, vitamins, prebiotics, probiotics, immune components, and other bioactive substances that shape early brain development. These elements may influence neural circuits involved in attention and impulse control.
Despite these benefits, many women across Europe do not breastfeed for the recommended duration. Barriers include health conditions, work schedules, and inadequate support. In such cases, infant formula—typically based on cow’s milk—remains the only recommended alternative during the first year of life.
The study’s findings come as European health systems grapple with rising rates of neurodevelopmental conditions. A separate analysis of biological ageing trends in younger adults has also raised concerns about long-term health trajectories. Under-50s Show Faster Biological Ageing, Linked to Rising Cancer Rates highlights how early-life factors can have cascading effects.
Solberg emphasised that the research does not prove causation but strengthens the case for supporting breastfeeding. “Neurodevelopmental disorders are shaped by multiple factors,” she said. “Our study suggests that breastfeeding duration and exclusivity may be one modifiable factor that could help reduce ADHD symptoms.”
The findings are particularly relevant for European policymakers and healthcare providers. The European Union has invested in maternal and child health programmes, and countries like Norway, Sweden, and Finland have among the highest breastfeeding rates in the world. Yet disparities persist, especially in southern and eastern Europe, where workplace policies and cultural norms vary widely.
As the continent faces new health challenges—from extreme heat stress to emerging infectious diseases—the importance of early-life interventions remains a priority. Extreme Heat Stress: Europe's Deadly New Normal as Study Reveals 40 Extra Days underscores how environmental changes are reshaping public health needs.
The Bergen study adds a nuanced layer to the conversation about breastfeeding and child development. It suggests that even modest increases in breastfeeding duration could yield measurable benefits for attention and behaviour, particularly for girls. For European families, the message is clear: supporting mothers to breastfeed exclusively for six months may have lasting neurological advantages.
