Deficiencies of DAT function play a major role in the pathophysiology of psychiatric disorders (for review see, e.g., Nikolaus et al., 2009b, 2010, 2012, 2014) and a variety of neurological conditions (for review see, e.g., Nikolaus et al., 2009a) including idiopathic and early-onset Parkinson’s disease (PD) and the “Parkinson Plus” syndromes multiple system atrophy and progressive supranuclear palsy. The gene discussed is SLC6A3; the disease is Parkinson disease.