Objective: There is a growing literature demonstrating a link between lower socioeconomic status (SES) and poorer neuroanatomical health, such as smaller total and regional gray and white matter volumes. Little is known, however, about the relation between SES and white matter integrity (WMI). Here we examined the relation between SES and WMI of the brain’s primary cortical regions, and evaluated potential moderating influences of age and self-identified race.

Participants and Methods: Participants were 192 neurologically intact, community-dwelling African American and White adults (mean age = 52 years; 44% male, 60% White, low SES = 52%) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study. Participants underwent 3.0-T cranial magnetic resonance imaging. Diffusion tensor imaging was used to compute fractional anisotropy (FA) to quantify the brain’s WMI. Multiple regression analyses examined independent and interactive associations of SES, age, and race with FA of the right and left frontal, temporal, parietal, and occipital lobes.

Results: There were no significant interactions of SES, age, and race for any region. However, significant main effects for SES were found for all regions, wherein individuals with low SES had lower FA (all ps < .05; Bs ranged from -.15 to -.28). Except for the right temporal lobe, main effects for age were found for all regions (all ps < .05; Bs ranged from -.18 to -.31), wherein older age was associated with lower FA. No main effects were found for race.

Conclusions: Novel findings of this study indicate that relative to the high SES group, low SES was associated with poorer diffuse WMI. These results may reflect the higher rates of environmental and interpersonal stressors encountered by those of lower SES across the lifespan, and may help explain the preponderance of functional disparities that exist between socioeconomic groups.