What is the difference between ADHD and ADD?

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If you’ve ever found yourself whispering “Is it ADHD… or ADD… or both… or neither…?” while Googling at midnight with one eye open, you’re in excellent company. Parents ask this all the time — usually with a mix of curiosity, mild exhaustion, and a cup of tea strong enough to power the National Grid.

So let’s clear it up once and for all, in a friendly way that won’t require a neuroscience degree or a second cup of coffee (though do feel free).

ADHD vs ADD: The quick, parent-friendly answer

Here it is in a nutshell:

ADD is an older term. ADHD is the term we use now.

The diagnosis ADD (Attention Deficit Disorder) no longer exists in modern diagnostic manuals. These days, everything falls under the umbrella of ADHD (Attention Deficit Hyperactivity Disorder) — even when hyperactivity isn’t present.

I know. It’s confusing. Blame the 1980s.

The three types of ADHD (yes, three!)

ADHD is now understood as three different presentations — because children and adults experience it in different ways.

1. ADHD – Inattentive Presentation (formerly known as ADD)

This is the group often described as “daydreamy,” “in their own world,” or “the child who loses their shoes while wearing them.”

Children with inattentive ADHD may:

• Struggle to focus or sustain attention

• Be forgetful or disorganised

• Miss details or instructions

• Find it hard to start or complete tasks

• Appear quiet or “no trouble at all” — which can delay support

  
  

2. ADHD – Hyperactive/Impulsive Presentation

This is the more outwardly active profile. Think:

• Constant movement

• Interrupting or talking a mile a minute

• Impulsive decisions

• Feeling “driven by a motor”

  
  

3. ADHD – Combined Presentation

This is when a child meets criteria for both inattentive and hyperactive/impulsive features.

For a formal explanation (without the bedtime-story tone), the CDC has a helpful overview:

ADHD (CDC Website)

Why did ADD disappear?

The shift to using ADHD for all presentations was made for two key reasons:

1. Science improved.

Research showed that the inattentive and hyperactive forms of ADHD share the same underlying neurological differences — just expressed differently.

2. Children without hyperactivity were being missed.

The old term “ADD” often described the quiet, thoughtful, imaginative child who struggled internally but didn’t wave their arms or bounce off furniture. These children were (and still are) at risk of slipping through the net.

By unifying everything under ADHD, clinicians aim to improve accuracy and access to support. The NHS and NICE both use this terminology today:

• NHS overview: 

• NICE guideline (ADHD diagnosis & management): 

“So… does my child have ADHD or ADD?”

If your child’s main struggles are with:

• concentration

• organisation

• memory

• follow-through

• focus

• zoning out

  
  

then they may fall under the “ADHD – Inattentive Presentation” category.

This is essentially what used to be called ADD.

If your child also shows noticeable hyperactivity or impulsivity, then the Combined or Hyperactive/Impulsive presentations might fit better.

A full diagnostic assessment looks at developmental history, behaviour across different settings, and the impact on daily life — whether at school, at home, or while attempting to put socks on in under 11 minutes.

Does understanding the difference actually matter?

Yes — and not just for tidying up the terminology.

Parents often tell us that finally understanding their child’s presentation helps them:

✔ Make sense of everyday difficulties

“Oh… this isn’t laziness. It’s inattentive ADHD.”

✔ Advocate at school

Teachers sometimes assume ADHD = bouncing off the walls. Understanding the inattentive type helps everyone support the child more effectively.

✔ Choose the right strategies

Children with inattentive ADHD often benefit from visual supports, gentle prompts, structured routines, and help breaking tasks into steps.

✔ Reduce frustration — for everyone

Life gets calmer when you know what’s going on under the surface.

Signs to look out for (without playing ‘Armchair Diagnostician’)​

While an official assessment is the only way to get a diagnosis, parents often notice things like:

• Difficulty staying focused on tasks

• Losing items constantly

• Missing details

• Forgetfulness

• Daydreaming

• Slow to start tasks

• Appearing overwhelmed by instructions

If you’re noticing a pattern — not just a “Tuesday morning” issue — it may be worth speaking to your GP or school SENCO, or seeking a formal neurodevelopmental assessment.

Support, next steps, and getting help

A diagnosis isn’t about labelling — it’s about understanding, access, and compassionate guidance, both at home and at school.

At NeuroDiverseKids.co.uk, our clinicians regularly assess for all presentations of ADHD in children and young people. If you’re feeling unsure, overwhelmed, or simply need a clearer roadmap, you’re not alone — and we’re here to help.

The NHS also offers helpful advice for parents: ADHD (NHS)

​Book an assessment or discuss treatment.