SLC6A3 and Parkinson disease: DA signalling is crucial in many neurological functions, as aberrations in DA neurotransmission contribute to multiple neuropsychiatric disorders, including addiction3, 45, Parkinson's disease and movement disorders46, 47, 48, schizophrenia49, 50 and attention-deficit hyperactivity disorder (ADHD)2, all of which have been linked to how extracellular DA may be mishandled by altered DAT expression and function23, 50, 51.