SLC6A3 and major depressive disorder: Using radiotracers with high selectivity for DATs, five studies compared DAT availability between people with MDD (n = 81) and healthy controls (n = 105) (Camardese et al., 2014; Hellwig et al., 2018; Meyer et al., 2001; Moriya et al., 2020; Pizzagalli et al., 2019).