Depressive Symptomatology, Racial Discrimination Experience, and Brain Tissue Volumes Observed on Magnetic Resonance Imaging.

Not much is known about brain structural change in younger populations and minorities. The cross-sectional relationship between depressive symptomatology and racial discrimination with structural measures of brain tissue volume was investigated using magnetic resonance images of 710 participants in the Coronary Artery Risk Development in Young Adults CARDIA Study in 2010. Those reporting depressive symptoms and racial discrimination had lower total brain matter volume compared with those who reported neither (-8.8 mL, 95% confidence interval (CI): -16.4, -1.2), those who reported depressive symptoms only (-10.9 mL, 95% CI: -20.4, -1.4), and those who reported racial discrimination only (-8.6 mL, 95% CI: -16.5, -0.8). Results were similar for total normal white matter. There were 103% higher odds (odds ratio = 2.03, 95% CI: 1.32, 3.14) of being in the highest quartile of white matter hyperintensities in those with depressive symptoms only compared to those without. Although tests for interaction by race were not statistically significant, sensitivity analyses stratified by race revealed inverse associations with total brain matter and total white matter volumes only among black participants with combined depressive symptomatology and experience of racial discrimination, and positive associations only among white participants with depressive symptoms with presence of white matter hyperintensities, suggesting future studies may focus on race.