What is ADHD?
Expert reviewed by Thomas E. Brown, PhD
ADHD is a common condition that makes it hard to focus, keep still, and think before acting. Some people with ADHD mainly have trouble with focus. (This is also known as ADD.) ADHD can also impact other skills, including managing emotions.
Snapshot: What ADHD is
ADHD is a common condition that’s caused by differences in the brain. People with ADHD have trouble with focus. But some are also hyperactive and impulsive. That’s especially true with kids and teens.
It’s not clear exactly how many people in the United States have ADHD. But estimates are between 5 and 11 percent.
People with ADHD have trouble with a group of key skills known as executive function. And that creates challenges in many areas of life, from school to work to everyday living. For example, people with ADHD often struggle to get organized, follow directions, and manage their emotions.
ADHD isn’t a matter of laziness or willpower — that’s one of many myths about it. In fact, people with ADHD are often trying as hard as they can to focus and keep their impulses in check.
For a long time, people thought ADHD was something only kids — boys, in particular — had. But research shows that adults also struggle with ADHD, and that women and girls probably have it as often as men and boys.
ADHD doesn’t just go away as people get older. Most of the time, hyperactivity and impulsivity lessen or disappear by the teen years or a little longer. But trouble with focus usually continues. Some people aren’t diagnosed with ADHD until after high school or as adults.
No matter when people are diagnosed with ADHD, there are treatments that can make symptoms more manageable. And there are supports that can make things easier at school and at work.
Dive deeper
Try a simulation to see ADHD through a child’s eyes.
Get answers to common questions about ADHD.
Explore a collection of ADHD personal stories.
ADHD signs and symptoms
The main symptoms of ADHD are trouble with focus, impulsivity, and hyperactivity. People can have them to varying degrees, and not everyone has all three. Symptoms can change, and some might go away with age.
The stereotype of kids with ADHD is that they’re always in motion, they’re impulsive and hyperactive, and that they act out at home and at school. But some people with ADHD never have those symptoms. They only struggle with focus. ADD is one name for this type of ADHD.
People with ADHD have trouble with executive function, which is the “management system” of the brain. Because of that, people with ADHD often struggle with:
Managing time
Getting and staying organized
Setting priorities
Planning
Managing emotions
Paying attention and remembering things
Shifting focus from one thing to another
Getting started on and finishing tasks
Thinking before saying or doing things
There’s one confusing sign of ADHD. People who have trouble focusing most of the time can often “hyperfocus” on tasks or activities they find really interesting.
For instance, a child might focus for hours while doing a craft project but drift off five minutes after starting homework. Or an adult may hyperfocus on video games or a TV show, to the point that they don’t hear their name being called.
Signs of ADHD can pop up at any age. Kids can show signs as young as preschool. But many don’t show signs until later on, as school gets harder and they have more to juggle. Some people don’t realize that what they experience is ADHD until they’re in college or working.
Dive deeper
Learn how boys may experience ADHD versus how girls often experience it.
For families: Understand the link between ADHD and lying.
For educators: Get evidence-based behavior strategies you can use in the classroom.
Possible causes of ADHD
There’s been a lot of research in the last few years pointing to possible causes of ADHD. Brain imaging studies have found differences and similarities in people with and without ADHD.
The research shows that brain development is very similar. But the areas involved in executive function take longer to develop in people with ADHD. That’s why kids with ADHD may act one to three years younger than other kids their age. Research also shows some differences in how the brain functions.
These differences have nothing to do with intelligence. People with ADHD are just as smart as people who don’t have it.
Researchers are also looking at the role of genetics. ADHD tends to run in families. A child with ADHD has a one in four chance of having at least one parent who has it. And there’s a strong likelihood that another close family member also has ADHD.
Read a dad’s candid story about moving past the guilt of “giving” his son ADHD.
Dive deeper
See how the ADHD brain is different.
Watch as an expert explains if ADHD ever goes away.
How ADHD is diagnosed
There are no tests for ADHD. Instead, evaluators use a variety of tools to determine if a child has ADHD. One is a questionnaire about behavior. Another is a clinical interview.
Here are some types of professionals who may diagnose ADHD:
General health care providers, including pediatricians
Psychiatrists
Developmental pediatricians
Neuropsychologists
Psychiatric nurse practitioners
Clinical psychologists
Watch as an expert explains the process for diagnosing ADHD.
Dive deeper
Find out how ADHD is diagnosed in adults.
For families: Find out what goes into an ADHD evaluation for a child.
For educators: If you suspect a student has ADHD, get tips on talking to the family.
How ADHD is treated
There are a few types of treatment for ADHD. They include:
Medication: Experts agree that this is the most effective way to treat ADHD in most kids and adults. There are two main types of medication for ADHD: stimulant and non-stimulant. Learn more about ADHD medication.
Behavior therapy: This type of therapy involves creating a rewards system for changing a child’s behavior. It’s different from cognitive behavioral therapy (CBT), which helps people look at their thoughts, emotions, and behaviors, and make positive changes. CBT may be helpful to some people with ADHD, but it’s not a treatment for ADHD.
Alternative treatments: There’s no shortage of companies that claim to have an all-natural fix to ADHD. Most have no evidence to back up their claims. Learn more about alternative treatments for ADHD.
ADHD doesn’t go away. But with the right treatments and supports in school, at home, and at work, people with ADHD can thrive.
Dive deeper
Explore a guide to ADHD medication.
For families: Considering ADHD medication for your child? Ask yourself these questions.
For educators: Learn about the power of praise in the classroom.
For parents and caregivers: Does your child have trouble with focus, hyperactivity, or impulsivity, or has your child been diagnosed with ADHD?
For educators: Do you have a student who struggles with attention, or who has accommodations for ADHD?
Do you think you might have ADHD?
Understood is not affiliated with any pharmaceutical company.
Key takeaways
ADHD is a biological condition that can impact focus, organization, and self-control.
ADHD is not a problem of laziness or willpower.
With the right support, people with ADHD can thrive.
