What is ADHD?

What is ADHD?

Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental (brain-based) condition.
It begins in childhood (before age 12) and can last across the lifespan.
ADHD involves difficulties with inattention and/or hyperactivity/impulsivity.
Inattention refers to wandering off task, seeming not to listen, being easily distracted, daydreaming, being disorganized, being forgetful, and losing materials.
Hyperactivity refers to over-activity, restlessness, fidgeting, talkativeness, and being unable to stay seated.
Impulsivity refers to intruding in other people’s activities (e.g. interrupting, blurting out), being unable to wait, and making hasty decisions without thinking about the potential consequences.
These difficulties must be beyond what would be expected for someone of the same age or developmental level.
ADHD occurs in most cultures in about 5% of children and about 2.5% of adults.

3 Types of ADHD:

The DSM-5 lists 3 types of ADHD: Inattentive Presentation, Hyperactive-Impulsive Presentation, and Combined Presentation.
The Combined Presentation is the most common, with 50-70% of individuals with ADHD having problems with both inattention and hyperactivity/impulsivity.
About 30% of individuals with ADHD only have difficulty with attention, while about 10% of individuals with ADHD only have difficulty with hyperactivity/impulsivity.


Symptoms affect each person to varying degrees (mild, moderate, and severe).
Symptoms may change from moment to moment and day to day.
Symptoms can depend on the setting or what the individual is doing.
Symptoms are often worse when the individual is bored, unsupervised, or doing something difficult.
Symptoms are often better when the individual is doing something he/she enjoys, when rewarded immediately, or when closely monitored.
Symptoms can change over time. For example, in adolescence/young adulthood, hyperactive symptoms are often less obvious than in childhood. However, difficulties with restlessness, inattention, poor planning, and impulsivity last over the lifetime. Many children with ADHD continue to struggle into adulthood.


ADHD is the official medical term for the condition.
Attention Deficit Disorder (ADD) is considered an old or outdated term for ADHD and was used in the past to describe the inattentive type of ADHD.
The newest way of thinking about ADHD is to think about significant symptoms, not specific types.

Executive Functioning

The executive functions are often defined as the mental skills required to plan, organize, and complete tasks.
These skills include attention, working memory, planning, organization, time management, self-control, and flexible thinking.
The executive functions can be thought of as the “air traffic controller” of the brain.
Executive functions are tied to brain development and do not fully develop until the early to mid-20s. Individuals with ADHD typically lag behind in the development of these skills (from 1 to 3 years).