What is the core neurobiological mechanism underlying ADHD?

At its core, ADHD involves differences in how brain networks regulate attention, motivation, and self control. The prefrontal cortex, which manages executive function, communicates less efficiently with reward and emotion centers. Dopamine and norepinephrine signaling play a major role. When these systems are under active, tasks that lack novelty or urgency are harder to initiate and sustain. This leads to difficulty with planning, follow through, and emotional regulation. ADHD is not about a lack of ability. It is about inconsistent access to regulation depending on context and stimulation.