SLC6A3 and bipolar disorder: Neurochemically, this behavioral dysregulation correlates with striatal dopamine transporter (DAT) downregulation-induced extracellular DA accumulation and concomitant prefrontal choline acetyltransferase (ChAT) suppression, mechanistically substantiating the catecholaminergic-cholinergic imbalance hypothesis of bipolar disorder while establishing construct validity (van Enkhuizen et al., 2015a).