SLC6A3 and Lewy body dementia: We found in the DLB group alone that lower caudate DAT concentration was associated both with greater functional impairment, as measured with the CDR-SB (R2 = 0.84 and P < 0.0001 for model; P = 0.0008 for interaction between caudate DAT concentration and diagnosis; Figure 2A), and with greater visuospatial impairment (R2 = 0.45 and P = 0.0006 for model; P = 0.008 for interaction between caudate DAT concentration and diagnosis; Figure 2B).