SLC6A3 and Alzheimer disease: A significant negative correlation between the HDRS scores and DAT availability was found in the AD/MD group (rho = −0.539, P = 0.012 for the striatum; rho = −0.435, P = 0.048 for the putamen; and rho = −0.558, P = 0.009 for the caudate), but not in the pure AD and healthy control groups (P > 0.05) (Fig. 4).