Maternal Mental Illness Affects Infant Neurodevelopment

INFANT neurodevelopment may be altered within the first year of life among children exposed to severe maternal mental illness, according to new findings that identified distinct patterns of brain activation and highlighted the influence of socioeconomic status on early neural development.

Brain Activation Patterns Reveal Infant Neurodevelopment Changes

Researchers investigated infant neurodevelopment in 60 infants aged 8–10 months. The cohort included 30 infants exposed to severe maternal mental illness and 30 unexposed controls. Brain activity was assessed using functional near-infrared spectroscopy during two experiments. One experiment compared neural responses to voice and non-voice sounds, while the second evaluated responses to sentences delivered with angry, happy, or neutral emotional prosody.

The study found evidence of atypical right temporal brain activation among infants exposed to severe maternal mental illness. In contrast to the control group, exposed infants demonstrated stronger activation in response to non-voice stimuli than to voice stimuli.

The findings suggest that infant neurodevelopment trajectories may diverge early in life following exposure to severe maternal mental illness. These differences were detectable before the age of 1 year, indicating that neural alterations can emerge during a critical period of developmental change.

The study additionally examined neural responses to sentences presented with angry, happy and neutral prosody, alongside analyses of the relationship between socioeconomic factors and patterns of brain activation.

Socioeconomic Status Influences Early Brain Development

A further finding was the association between socioeconomic status and patterns of neural activation. Higher socioeconomic status was positively correlated with activation to non-voice stimuli and with activation to spoken sentences, irrespective of emotional prosody.

Additional analyses revealed that neural responses to non-voice stimuli mediated the relationship between socioeconomic status and activation to sentences. These findings suggest that enhanced neural responses to non-voice stimuli may play a protective role when social stimulus processing is atypical.

Conclusion

Taken together, the results indicate that infants exposed to severe maternal mental illness follow distinct neural developmental trajectories compared with unexposed infants. The data also signify the importance of socioeconomic status as a factor associated with early brain function. The researchers concluded that both maternal mental illness exposure and socioeconomic background may play important roles in shaping infant neurodevelopment during the first year of life.

Reference

Piatti A et al. Early detection of distinct language development in infants of mothers with severe mental illness using fNIRS. Commun Psychol. 2026;DOI:10.1038/s44271-026-00475-y.

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