 Current models of ADHD suggest that it is associated with functional impairments in some of the brain 's neurotransmitter systems , particularly those involving dopamine and norepinephrine . The dopamine and norepinephrine pathways that originate in the ventral tegmental area and locus coeruleus project to diverse regions of the brain and govern a variety of cognitive processes . The dopamine pathways and norepinephrine pathways which project to the prefrontal cortex and striatum are directly responsible for modulating executive function ( cognitive control of behavior ) , motivation , reward perception , and motor function ; these pathways are known to play a central role in the pathophysiology of ADHD . Larger models of ADHD with additional pathways have been proposed . 
