ADGRL3 and attention deficit-hyperactivity disorder: Likewise, adult Lphn3−/− mice demonstrate overexpression of Slc6a3 in whole brain36 and in the dorsal striatum,34 but downregulation of Slc6a3 in the PFC.35,69 DAT expression is associated with ADHD, cocaine addiction, and alcoholism (see ref. [73] for review] making these results noteworthy.