Relationship between structural brain differences and social factors associated with neurodevelopmental disorders: A systematic review

Advances in neuroimaging have substantially improved our understanding of the biological mechanisms underlying neurodevelopment. Although relevant studies are scarce, social determinants, particularly socioeconomic status (SES) appears to play a crucial role in typical and atypical brain development. Different methods and scales are used to evaluate SES. The aim of this systematic review was to investigate the influence of SES on brain structure in neurodevelopmental disorders (NDDs) and its potential impact on the diagnosis and severity of NDDs. The 1423 entries extracted from six databases were imported into Covidence, and 13 (7 cohort, 4 case-control, and 2 cross-sectional) studies were included in our final synthesis, encompassing a combined sample of 33,789 participants. The SES indicators used by the studies included measures of income, residential neighbourhood, and educational levels and seem to be associated with structural changes in neurodevelopment throughout life. During the early stages of development, maternal SES impacts children's brain structure and behavioural and cognitive outcomes. At older ages, parental schooling continues to be a determining factor for cognitive performance, while differences in brain structure become more evident and associated with NDDs such as attention deficit/hyperactivity disorder.