The Inequality of Neural Destiny: Signatures of Lifecourse Socioeconomic Conditions in Markers of Brain Tissue Myelination and Volume

Socioeconomic status (SES) plays a significant role in health and disease. At the same time, early-life conditions affect neural function and structure, suggesting the brain may be a conduit for the biological embedding of SES. Here, we investigate the neural signatures of SES in a large-scale population cohort aged 45 to 85 years. We assess both grey matter volume (GMV) and magnetization transfer (MT) saturation, indicative of myelin content. Higher SES in childhood and adulthood associated with more GMV in several brain regions, including postcentral and temporal gyri, cuneus, and cerebellum, while low SES correlated with larger entorhinal cortex volume. High childhood SES was linked to more widespread GMV differences and higher myelin content in the sensorimotor network while low SES correlated to myelin content in the temporal lobe. Crucially, childhood SES differences in adult brains persisted even after controlling for adult SES, highlighting the unique contribution of early-life conditions to neural status in older age, independent of later changes in SES. These findings inform on the biological underpinnings of social inequality, particularly as it pertains to early-life conditions.