ADHD is a neurodevelopmental condition affecting approximately 5-7% of children and 2-5% of adults, characterized by persistent difficulties with attention, hyperactivity, and impulsivity. From a cognitive perspective, ADHD involves deficits in executive function — particularly sustained attention, inhibitory control, and working memory — along with altered reward processing and motivation.
Cognitive Profile
Russell Barkley's influential model characterizes ADHD primarily as a disorder of behavioral inhibition, with downstream effects on working memory, self-regulation, internalization of speech, and reconstitution (analysis and synthesis of behavior). Neuroimaging studies consistently show structural and functional differences in prefrontal cortex, basal ganglia, and cerebellar circuits. Dopamine and norepinephrine system dysfunction is implicated, as stimulant medications that increase catecholamine availability are the most effective pharmacological treatment.
ADHD research has contributed to understanding of normal attention and executive function by revealing what happens when these systems are compromised. Findings include greater variability in reaction times (reflecting inconsistent attention), steeper temporal discounting (preferring smaller immediate rewards over larger delayed ones), and impaired time perception and time management. These cognitive characteristics have practical implications for educational accommodations and behavioral interventions.