A new study released on June 11 suggests that variables linked to socioeconomic status, such as increased stress and reduced sleep, have strong relationships with brain structure and function in children.
Lucinda M. Sisk and Theodore D. Satterthwaite wrote in a related Perspective that "although previous work has found that socioeconomics can affect brain structure and function, [these authors] demonstrate these effects with notable scale and consistency." Brain-wide association studies examine how variability in brain structure or function across many people relates to differences in behavior, mental health, or environmental exposures. Such studies often evaluate measures like functional connectivity and cortical thickness, which can vary among individuals over time.
In this research, Scott Marek et al. sought to identify which exposures from 649 different variables were most strongly associated with functional connectivity and cortical thickness in a sample of youth aged 9 to 10 from the Adolescent Brain Cognitive Development Study. The authors found that a composite of factors related to socioeconomic status—including family income and neighborhood opportunity—were most strongly associated with functional connectivity.
The study showed that SES-associated differences were strongest in brain regions involved in sensory and motor processing. Screen time and reduced sleep—both linked to lower socioeconomic status—showed the strongest associations within these regions. The authors said it is possible that stressors related to socioeconomic status may alter arousal patterns over time because these regions are related to arousal, potentially producing lasting differences in brain function.
Marek and colleagues replicated their findings using data from the UK Biobank sample (composed primarily of white British, white Irish, or other white backgrounds). Combined with analyses stratified by genetic ancestry in the original youth sample, these results indicate that observed brain differences are unrelated to genetic ancestry. Marek's team noted it "remains unclear when strong associations between the brain and SES first emerge or when environmental interventions may be most beneficial," but emphasized, "socioeconomic opportunity is not destiny." They suggested interventions targeting sleep quality and chronic stress could help bolster children's brain development.
