ADHD Versus ADD: What’s the Difference?

You may have heard the terms ADD and ADHD – but are they the same condition? This article will explain the history of the terms, ADHD symptoms, and how ADHD impacts communication for children and adults.

By Ability Central

17 May, 2024

Two white, elementary-aged children, a boy and a girl, laugh while playing with fidget spinners in their house's front yard

Is there a difference between ADD and ADHD?

Most people have heard of attention-deficit/hyperactivity disorder, or ADHD. But what about other terms, like ADD or attention-deficit/hyperfocus disorder? Are they all referring to the same thing?

This article breaks down ADD and ADHD by answering the following questions: 

  • What is the difference between ADD and ADHD?
  • Why do people still use the term ADD?
  • What are the symptoms of ADHD?
  • Is ADHD a sign of autism?
  • How does ADHD affect communication?
  • What conditions co-exist with or mimic ADHD?
  • Why do so many people have ADD/ADHD? What causes it?
  • Can I self-identify with ADHD without having an evaluation?
  • What is the ADHD assessment process?
  • Where can I find ADHD testing near me?
  • Where can I learn more about ADHD and similar conditions?


What’s the difference between ADD and ADHD?

Are ADD and ADHD the same thing? The short answer: Yes. 

ADD is an out-of-date version of the diagnosis we know today as attention-deficit/hyperactivity disorder, or ADHD.

ADHD affects about:

  • 5% of children between the ages of 5 and 11
  • 11% of children between the ages of 4 and 17
  • 3% of adults

ADHD is known for symptoms like impulsivity, hyperactivity, and difficulties with focus, concentration, memory, and motivation. 

This set of symptoms used to be known as attention deficit disorder (ADD). The Diagnostic and Statistical Manual (DSM), the standardized guidebook widely used by mental health professionals, defines differences to mental health or neurological conditions like ADHD in each updated edition.

The clinical definition of ADHD has been through many iterations of the DSM, from attention-deficit disorder (ADD) in 1980 to attention-deficit hyperactivity disorder (ADHD) in 1987, and finally to attention-deficit/hyperactivity disorder (also ADHD) in 1994. 

And yes, the forward slash matters! Doctors use this updated grammar to highlight that people with ADHD can have one of three subtypes, now called presentations. These include:

  • Predominantly inattentive presentation. People with this form of ADHD struggle with things like organization, deadlines, and paying attention to conversations.  
  • Predominantly hyperactive-impulsive presentation. People with this form of ADHD tend to talk a lot, interrupt others, make impulsive decisions, and struggle to sit still. 
  • Combined presentation. People with this form of ADHD show signs of both inattentive and hyperactive-impulsive presentations. 


If it’s outdated, why do people still use the term ADD?

A common misconception about ADHD is that someone “has” to show symptoms of hyperactivity to receive an ADHD diagnosis. According to the Child Mind Institute, however, the diagnosis of ADHD can still apply even if a person does not have hyperactive or impulsive behaviors. 

Some parents have said things like, “My child isn’t hyperactive, so she can’t have ADHD.” However, this is an incorrect use of an outdated term, and can be confusing for medical professionals as well as for people with the diagnosis.

In cases where someone shows signs of ADHD but is not hyperactive, the correct diagnosis would be “attention-deficit/hyperactivity disorder, predominantly inattentive presentation.”


What are the symptoms of attention-deficit/hyperactivity disorder?

The brains of people with ADHD are structurally different. Because of these structural differences, children with ADHD have trouble focusing and behaving. 

Other ADHD symptoms include:

  • Fidgeting or tapping hands and feet
  • Talking too much
  • Interrupting others
  • Difficulty staying focused
  • Difficulty completing tasks 
  • Struggling with prioritization and time management
  • Difficulty creating and maintaining relationships

To learn more, see ADHD Symptoms and Early Signs.


Is ADHD a sign or form of autism?

ADHD and autism spectrum disorders (ASD) share similar symptoms, but they are not the same condition. A person can have both ADHD and autism, but having one condition is not a guarantee they will have the other. 

So, is ADHD a sign of autism? Does autism cause ADHD? The simple answer is no. Particularly in children, ADHD is often mistaken for autism, and vice versa.

Of the differences between ADHD and autism, the largest is that most people with ADHD are overwhelmed by and react constantly to outside stimuli, while people with autism tend to intensely focus on one thing. 

This can happen in ADHD too (called hyperfixation), but most ADHD hyperfixations tend to go away with time, while autism fixations are often lifelong. For example, a child with ADHD might be obsessed with a certain TV show for a week before moving that passion to a new show, while a child with autism might hold onto that interest for many years. 


How does ADHD affect communication in children?

ADHD can make communication complicated for both children and adults. 

Children with ADHD may struggle to make friends. Some kids with ADHD have difficulty:

  • Sharing or taking turns
  • Managing their emotions
  • Following rules
  • Noticing other people’s feelings or body language
  • Concentrating on other people and listening to what they say
  • Listening without interrupting

If left untreated, these symptoms can turn into other communication challenges in adulthood. 


How does ADHD affect communication in adults?

Many adults with ADHD don’t know that they have it. In fact, research shows that less than 20% of adults with ADHD receive a diagnosis and treatment for their symptoms. 

While adults with ADHD may have the same symptoms they exhibited as children, these symptoms may appear in different ways. For example, an adult with predominantly hyperactive/impulsive ADHD might:

  • Have workaholic tendencies
  • Gamble a lot, or make risky decisions like driving too fast
  • Struggle with substance abuse
  • Fidget constantly
  • Change jobs a lot 

Meanwhile, an adult with predominantly inattentive ADHD might: 

  • Struggle to remember important dates like anniversaries and birthdays
  • Forget appointments
  • Show up late
  • Struggle to complete a project from start to finish
  • Frequently lose belongings like keys and wallets
  • Be very disorganized, both with work/school tasks and their personal belongings

These symptoms can be very frustrating for someone with ADHD and their loved ones. Loved ones may feel neglected or unappreciated if a friend or partner with ADHD forgets their birthday, fails to do their half of chores, or shows up late to events. 

On the other hand, an adult with ADHD who exhibits these behaviors may get frustrated with themselves, have low self-esteem, or think there is something “wrong” with them. 

Ultimately, people with ADHD can have fulfilling, authentic relationships and careers with proper treatment and therapy. New skills like time/task management, appointment tracking, and productivity software can help adults with ADHD succeed socially and in the workplace. 

An ADHD diagnosis, no matter when it’s received, can be powerfully validating. Looking back on childhood and early adulthood, someone who has recently discovered they have ADHD may notice events or behaviors that at the time felt frustrating and overwhelming but were really related to undiagnosed ADHD. 

It’s never too late to start ADHD treatment. Many people diagnosed “late” with ADHD see huge improvements in focus, productivity, and restlessness with treatment like medication and therapy.


What conditions co-exist with or mimic ADHD?

About 85% of adults who are diagnosed with ADHD also have at least one other psychiatric or developmental disorder. Your doctor may suggest other tests and screenings for:


Why do so many people have ADD/ADHD? What causes it?

There is no one cause for ADHD, but research shows potential connections in genetics and brain development. Some doctors shy away from the term “disorder” for ADHD, preferring to call it a form of neurodiversity. 

Contrary to popular belief, no research supports any of the following causing ADHD:

  • Overeating sugar
  • Watching too much television
  • Parenting methods
  • Poverty
  • Family chaos

To learn more about the causes and risk factors for ADHD, see ADHD Quick Facts.


Can I self-identify without going for an ADD/ADHD evaluation?

There is an online quiz to help adults evaluate their ADHD symptoms at home, but it is only a starting point. An official diagnosis requires a thorough assessment from a healthcare professional.

This assessment might include:

  • Psychiatric medical history 
  • Physical medical history
  • Family history 
  • Screenings to rule out other diagnoses


What is the ADD/ADHD assessment process?

There is no single ADD and ADHD test to confirm a diagnosis. However, a healthcare provider will likely use other tests to rule out conditions that mimic ADHD. Those tests may include:

  • Hearing tests
  • Vision tests
  • Blood tests
  • A test to measure electrical activity in the brain
  • A CT scan or MRI to check for brain abnormalities


Where can I find ADD/ADHD doctors near me?

Ability Central offers a nonprofit database that can help you connect with organizations in your area that serve people with neurodiverse conditions like ADHD. Use our Service Locator tool to find a nonprofit that can connect you with healthcare providers, support groups, and therapists in your area.


Where can I learn more about ADD/ADHD and similar conditions?

Ability Central has a library of resources to help you learn about ADHD and related conditions. See:

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