SLC6A4 and Lewy body dementia: A significant positive correlation between the volume of s129 and SNAP25 within presynaptic 5HTT terminals was observed in DLB overall (rs = 0.288, p = 0.012), non-depressed DLB (rs = 0.313, p = 0.016) and DLB with depression (rs = 0.316, p = 0.030; Fig. 4).