What is ADHD?
October 1, 2026
ADHD is a neurodevelopmental disorder affecting both children and adults. It is described as a “persistent” or ongoing pattern of inattention and/or hyperactivity-impulsivity that gets in the way of daily life or typical development. Individuals with ADHD may also have difficulties with maintaining attention, executive function (or the brain’s ability to begin an activity, organize itself and manage tasks) and working memory.
- Inattentive
- Hyperactive-impulse
- Combined inattentive & hyperactive-impulsive
Inattentive presentation:
- Fails to give close attention to details or makes careless mistakes.
- Has difficulty sustaining attention.
- Does not appear to listen.
- Struggles to follow through on instructions.
- Has difficulty with organization.
- Avoids or dislikes tasks requiring sustained mental effort.
- Loses things.
- Is easily distracted.
- Is forgetful in daily activities.
Hyperactive-impulsive presentation:
- Fidgets with hands or feet or squirms in chair.
- Has difficulty remaining seated.
- Runs about or climbs excessively in children; extreme restlessness in adults.
- Difficulty engaging in activities quietly.
- Acts as if driven by a motor; adults will often feel inside like they were driven by a motor.
- Talks excessively.
- Blurts out answers before questions have been completed.
- Difficulty waiting or taking turns.
- Interrupts or intrudes upon others.
Combined inattentive & hyperactive-impulse presentation:
- Has symptoms from both of the presentations.
Reference:
American Psychiatric Association (2013). Diagnostic and statistical manual of mental disorders (DSM-5), Washington, D.C.: American Psychiatric Association