Whole brain 3D maps of significant associations between homocysteine levels and regional cortical gray matter (GM) volumes in the left and right hemispheres of all N=803 subjects, (A) after controlling for age and sex (left: −log10(p-value)=1.673–3.930, right: −log10(p-value)=1.663–3.920, FDR corrected) and (B) after controlling for age, sex, and diagnosis (AD, MCI, or healthy elderly) (left: −log10(p-value)=2.204–4.462, right: not significant, FDR corrected). Results were corrected for multiple comparisons by thresholding at a p=0.05 false discovery rate (FDR) threshold across the entire brain surface. Blue areas represent points on the cortical surface where p-values passed the corrected significance threshold for a negative relationship between homocysteine levels and cortical GM volumes (higher levels of homocysteine associated with lower cortical GM volumes). No areas of significant positive associations were found.