Infant brain networks develop differently in families with ADHD history, small study suggests

A small longitudinal study found stronger increases in frontoparietal connectivity among infants with a parental history of ADHD, but researchers stress that the preliminary findings need replication.

A small longitudinal study in Frontiers in Neuroscience suggests that differences in brain connectivity linked to attention may be detectable in the first year of life, particularly among infants with a family history of attention-deficit/hyperactivity disorder.

Researchers followed 44 infants, evenly split between those with and without a parental history of ADHD, at roughly 9 months and again at about 13 months. Using functional near-infrared spectroscopy, or fNIRS, they measured activity in frontal and parietal regions while the babies watched a low-demand abstract film designed to keep their attention without placing heavy cognitive pressure on them. The same families later completed behaviour ratings when the children were toddlers.

Across the full sample, the team observed a rise in frontal connectivity over time, along with a shift towards the left side of the brain. The clearest change was an increase in communication between the left dorsolateral prefrontal cortex and the right parietal region, a connection that was more pronounced in the higher-risk group. Children with familial ADHD risk showed stronger increases in frontoparietal connectivity than their lower-risk peers, while the low-risk group showed a decline in the same pathway. The researchers said this pattern may point to different routes of network development in infancy, although they stressed that most findings did not survive strict statistical correction and therefore remain preliminary.

The study also found that toddlers with more parent-reported attention problems tended to show greater increases in frontoparietal connectivity during infancy. That pattern broadly matched the group-level results, hinting at a possible shared neural signature of early ADHD vulnerability. The authors argued that fNIRS could eventually help identify infants who might benefit from earlier monitoring or preventive support, but they also cautioned that the sample was small and that the infant connectome changes rapidly during this stage of development, making replication essential.