Dr. Hahn's laboratory investigates genetic variation in the human norepinephrine transporter (hNET) in human psychiatric and cardiovascular disorders, including attention-deficit hyperactivity disorder (ADHD) and major depression, and examines the link between genetic variation and symptoms shared across disorders. The lab employs cell culture and animal models to examine the consequences of hNET genetic variation on hNET protein expression, activity, regulation by signal transduction pathways and cognitive and cardiovascular dimensions.