a neurodevelopmental disorder marked by persistent inattention, hyperactive or impulsive behavior, or both

: ADHD is a neurodevelopmental disorder marked by persistent inattention, hyperactive or impulsive behavior, or both.

a neurobiological disorder and not merely a childhood affliction that affects individuals across the lifespan,

​ADHD is a neurobiological disorder that affects individuals across the lifespan, and not merely a childhood affliction.

a complex disorder

ADHD is a complex disorder, manifesting in slightly different ways in each person who has ADHD .

an ongoing condition that affects children, adolescents, and adults of all ages

ADHD is an ongoing condition that affects children, adolescents, and adults of all ages.