Parental mental illness and child brain structure : a diffusion MRI study of emotion regulation related pathways

Abstract

Background: Children of parents with mental illness (at-risk) face an increased risk for developing mental health issues themselves than children of healthy parents (controls), yet the neurobiological underpinnings remain unclear. This study explored differences in white matter (WM) between at-risk children and controls, focusing on brain pathways related to emotion regulation and the associations between parenting behaviours, stress, and WM microstructural properties. Methods: WM properties were assessed via diffusion-weighted imaging in 64 children (28 at-risk, 36 control) across five emotion-related pathways. Multiple regression analyses examined pathway alterations between groups and associations between parenting behaviours, parenting stress, emotion regulation and WM pathways across all participants beyond effects of group membership, controlling for socioeconomic status, age, sex, scanning site and global WM volume. Results: At-risk children showed alterations in the right inferior longitudinal fasciculus (ILF), indicated by higher fractional anisotropy and lower mean diffusivity. Across groups, dysfunctional parenting was associated with widespread WM alterations, including the corpus callosum (CC) genu, bilateral dorsal cingulum, bilateral ILF, in parts of the superior longitudinal fasciculus and left uncinate fasciculus. Additionally, lower partnership support was specifically linked to alterations in the CC genu. No significant associations were found between WM microstructure and children’s self-reported emotion regulation. Conclusions: These findings show potential evidence of altered WM pathways in children at-risk for mental illness, particularly in emotion regulation related pathways. Additionally, parenting behaviour and stress were associated with WM microstructure in children, underscoring potential influence of early environmental factors on brain development. Longitudinal and replication studies are needed to clarify causal mechanisms and long-term effects.