Scatter plots show homocysteine levels and mean cortical gray matter (GM) thickness (A, mm) or total cortical GM volume (B, mm2) for all N=803 subjects in statistical regions of interest. Data is shown for regions with a significant association between homocysteine levels (μM) and cortical GM measures in the whole brain, after controlling for age, sex, and dementia, FDR corrected (panel B in Figures 1 and 2). Healthy control subjects are shown with green triangles, subjects with mild cognitive impairment are shown with red circles, and subjects with Alzheimer’s disease are shown with black squares.